The quietening part 2: rules

Apply some rules about what notifications are automatically
silenced.

Test: make ExtServicesUnitTests &&
adb install -r $OUT/testcases/ExtServicesUnitTests/ExtServicesUnitTests.apk &&
adb shell am instrument -w android.ext.services.tests.unit/android.support.test.runner.AndroidJUnitRunner
Bug: 111475013

Change-Id: Idf0434c0688b3249a9fc2d5aa655665e71e53249