Merge "Reset the alpha value of ALL notification content views" into sc-v2-dev am: f49cf8a413 am: 1dc72ae9c9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16379053

Change-Id: Ic8bdd811f656d40074f55c917b8e2cdd389f0742