Downloading Earlier SDK Versions
Android Studio provides the SDK and the emulator system image from the latest platform. However, you may want to test your apps on earlier versions of Android.
You can get components for each platform using the Android SDK Manager. In Android Studio, select Tools → SDK Manager. (You will only see the Tools menu if you have a project open. If you have not created a project yet, you can instead access the SDK Manager from the Android Welcome dialog. Select Configure → SDK Manager.)
The SDK Manager is shown in Figure 1.
Figure 1 Android SDK Manager
Select and install each version of Android ...