Merge "Prevent bell icon from disappearing on immediate followup notification." into rvc-qpr-dev am: a568597191 am: e35f399130

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12099423

Change-Id: Ief08af5a5d4f46c4cbefc84713b0bf2498e687b0