Introduce Gradle Managed Device definitions to modules that have instrumented tests.
At the moment, defining it as a convention plugin isn't possible due to the bug. That bug is now fixed and will be included in Android Studio Flamingo.
Once Flamingo becomes stable, convert the GMD definitions as a convention plugin (#523)
Change-Id: I0866369e3d0bbe148ca5ec1f92bad59239a347b8
Takeshi Hagikura