Errata

Just a question:

Now that Android Studio has changed the app wizard's default activity layout template to use by default a ConstraintLayout from the support library instead of the standard framework's RelativeLayout, do you plan to update this section accordingly (to show the generated activity_main.xml layout file with a root ContraintLayout)?
Because I guess that would be too much of a hassle (of a rewrite), wouldn't it?!

Maybe there's an easier solution to this challenge:

Given that there's some time left before your fine book is going to print, and assuming that the two of you might be on good terms with Google's tools team that's responsible for Android Studio (or could send a note to Reto Meier), how about this:

Why not just ask them politely :-) to put in the app wizard, within the "Customize the Activity" screen, a textbox or spinner below the name of the layout file that's going to be created, somewhat like this:

Activity Name: [MainActivity ]
[X] Generate layout file?

Layout file name: [activity_main ]
[X] Backwards compatibility? (AppCompat)
Root layout: [ConstraintLayout ]

That would be kind of a win-win situation, because
a) that's what the "New Activity" wizard already offers anyway, and
b) I assume there's quite a couple of devs out there who would
appreciate this feature, too, and
c) it would only require you to indicate to your readers to exchange the
"ConstraintLayout" for a "RelativeLayout", without much of a rewrite.

Cheers,
ikr

P.S.
There's of course the possibility to edit the templates used by the wizards.
stackoverflow.com/a/36654035/3141545
For beginners however, that would probably not be the option of choice!?

Note from the Author or Editor:
We've written a new chapter for the latest version of the book that covers constraint layouts.

The link provided to check for the required JDK version now points to the mere hardware requirements.
developer.android.com/sdk/index.html#Requirements

That's because Android Studio 2.2 and higher versions come bundled with a version of OpenJDK, which is also the recommended version to be used for app development in Android Studio:
developer.android.com/studio/intro/studio-config.html#jdk

So you may want to update this section accordingly.
"The times they are a changin'" Bob Dylan, 1964
;-)

Change of naming convention starting with Support Library release 24.2.0 (August 2016)

Your second paragraph below the image states that:

"The name of the support library reflects the lowest version number of
Android the library is compatible with."

This has been true prior to version 24.2.0 of the Support library.
Starting with version 24.2.0 however, this has changed. The minimum API level for (most) support libraries has been increased to API level 9.

Please see the following links:

https://developer.android.com/topic/libraries/support-library/index.html
...and especially the "Caution" subsection.

https://developer.android.com/topic/libraries/support-library/index.html#api-versions

Note from the Author or Editor:
We've removed the paragraph that talks about which support libraries work with which API levels. We've adjusted the nearest available NDQs as follows:

"Q: What versions of Android can the Support Libraries be used with?
"A: It depends on the version of the Support Library. Prior to version 24.2.0, Libraries prefixed with v4 could be used with API level 4 and above, and those prefixed with v7 could be used with API level 7 and above. When version 24.2.0 of the Support Libraries was released, the minimum API for all Support Libraries became API level 9. The minimum API level is likely to increase in the future."

=This is an update to my question/suggestion as of Apr 20, 2017 =
= (Early Access version of book) =

In my above mentioned suggestion I've pointed out that the minimum SDK version for most APIs contained in the Support Library has been increased to API level 9, starting with Support Library version 24.2.0.

Now, can you hear Britney Spears singing "Oops!...I Did It again"?!
As of revision 26.0.0 Alpha 1 they've increased that minimum SDK level even further, to SDK level 14.

https://developer.android.com/topic/libraries/support-library/revisions.html#26-0-0-alpha1

Couldn't they just have waited 'till *after* the publishing of this fine book?!
:-)

Note from the Author or Editor:
We've removed the paragraph that talks about which support libraries work with which API levels. We've adjusted the nearest available NDQs as follows:

"Q: What versions of Android can the Support Libraries be used with?
"A: It depends on the version of the Support Library. Prior to version 24.2.0, Libraries prefixed with v4 could be used with API level 4 and above, and those prefixed with v7 could be used with API level 7 and above. When version 24.2.0 of the Support Libraries was released, the minimum API for all Support Libraries became API level 9. The minimum API level is likely to increase in the future."

Maybe add versions 7.1 and 7.1.1 Nougat API Level 25 to the table?
(Who'd want to miss out on the GIFs and stickers enabled keyboard?!)
:-)

More recent Android Studio versions show in the App wizard's "Customize the Activity" page below the layout name the additional option to allow for "Backwards Compatibility (AppCompat)" which is ticked by default.
Maybe exchange the screenshot for an up-to-date one and also advise the users to "leave the checkbox ticked", because otherwise...havoc.
;-)

Note from the Author or Editor:
We've changed all the screenshots and instructions in the latest version of the book to reflect the changes to Android Studio.

"You can find system resources in
the res folder.
..."

Maybe that should read:
"You can find app resources in
the res folder.
..."

While indeed a good deal of the resources found there have been automatically provided _by_ the Android system, the "system resources" actually reside in a not-so-mundane, affluent neighborhood.
But that's of course just splitting hairs...
;-)

"Make the text wrap horizontally and vertically"
Actually, no.
It commands the layout to "Make the element just wide and tall enough to accommodate for the text size's (contents) needs"

Splitting hairs, again. I know...<sigh>

Note from the Author or Editor:
We've changed the wording to "Allow the text to wrap horizontally and vertically"

The 4th paragraph describes the path the menu resource .xml file will be placed in:

"We’re going to create a new menu resource file called menu_main.xml in
the folder app/src/main/res/menu. All menu resource files go in this folder."

OK so far. However, the next paragraphs states:

"To create the menu resource file, highlight the app/src/main/res folder,
go to the File menu, and choose New. Then choose the option to create
a new Android resource file."

Which would have that menu_main.xml file float around directly in the /res folder.
Thus, perhaps update these paragraphs somewhat like so:

"To create the menu resource file, first check if Android Studio has already created a menu resources folder for you, at app/src/main/res/menu.
If such a menu folder doesn't exist yet, just create it now by right clicking on the /res folder and selecting "New | Android resource directory" and selecting "menu" from the "Resource type" drop down.
Once that menu folder exists, highlight it, go to the File menu, and choose New. Then choose the option to create a new Android resource file."

Note from the Author or Editor:
We've added extra instructions to make sure the directory name in the dialog is "menu". This creates the menu folder and adds the menu resource file to it.

Maybe advise the reader to use the resolveActivity() method

I know there's hardly room for extensive answers within these Q/A pairs.
However, maybe you'd still like to point the reader to using the resolveActivity() method on the send intent wrapped in an if(...) condition, as described in:

https://developer.android.com/guide/components/intents-filters.html#ExampleSend

instead of wrapping the startActivity() call in a try/catch block?

Best regards,
ikr

Note from the Author or Editor:
We've removed the second paragraph on that page, and replaced the final sentence in the final answer with "You can check whether any activities on the device are able to receive the intent by calling the intent's resolveActivity() method and checking its return value. If its return value is null, no activities on the device are able to receive the intent, so you shouldn't call startActivity(). "