Potential fix: Your project's AGP version is typically defined in the plugins block of the `settings.gradle` file (/b/s/w/ir/x/w/flutter/dev/integration_tests/android_engine_test/android/settings.gradle), by a plugin with the id of com.android.application. 
If you don't see a plugins block, your project was likely created with an older template version. In this case it is most likely defined in the top-level build.gradle file (/b/s/w/ir/x/w/flutter/dev/integration_tests/android_engine_test/android/build.gradle) by the following line in the dependencies block of the buildscript: "classpath 'com.android.tools.build:gradle:<version>'".

Warning: SDK processing. This version only understands SDK XML versions up to 3 but an SDK XML file of version 4 was encountered. This can happen if you use versions of Android Studio and the command-line tools that were released at different times.
Running Gradle task 'assembleDebug'...                             35.4s
✓ Built build/app/outputs/flutter-apk/app-debug.apk
Installing build/app/outputs/flutter-apk/app-debug.apk...        1,000ms
Step failed (timeout) (retcode: -15)