Merge "Limit the number of concurrent notifs appear on screen am: abe9246c am: 8c385c26" into sc-v2-dev-plus-aosp am: edddc0f3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/15531757

Change-Id: Idf881c7fc3265e5f12e243eecfd8353ec456abe5