Merge "Promote FeatureFlag best practices in notifications code & tests" into udc-qpr-dev am: febba3b65f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23984923

Change-Id: Id7846768a2f0ef9068f6fb59f6e0ddb75655d1e2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>