Merge "Adds listener support to FakeFeatureFlags" into tm-qpr-dev am: 34fdbdb5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/19763934



Change-Id: Ie02e30fd5f2ebc251a46092db81d17691678ede9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>