Merge "Add slow fade-in to notification shelf icon to prevent overlapping...

Merge "Add slow fade-in to notification shelf icon to prevent overlapping icons in the shelf." into sc-dev am: afa8c993

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14882394

Change-Id: Ia9b936e0fc5999b7ef5ae2a25055a0a296cc67dd