Fixes #137600
Protect flutter analyze --suggestions from null error when AGP value is missing
Update template with a reference to new agp definition location
Look for AGP version being set in settings.gradle (change to templates happened in dbe0ccd885 (diff-20537fb84ee37894a3f3d9723a06bcf2674290ee25aa83332c2524a1f7546a6d)