Merge "Revert "Revert "Update theme for ChannelPanelActivity""" into udc-dev am: 185244f43d

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/23467968

Change-Id: Ice47c201387d778d3bee0aa239fdd3b3eb59a031
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>