Merge "Fixing notifications background in split shade mode" into sc-dev am: d319fb00 am: 7f6a3652 am: b0fb1f8e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14389531

Change-Id: Ida41203b41c4be8c3bcc7f3dd80fbc36b08da307