Merge "Change Notification expander to use 10% opaque foreground color" into udc-qpr-dev am: a21164e9ef am: e84f770b29

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24358096

Change-Id: Ie620cbd62a2f33153106a4c9fbb30a8ed9fc0839
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>