Add dimensions for notification channel panel am: 42ac382a am: 4b733b24

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/21334700



Change-Id: I94425217f087d755babd9c27d4a058c0d6e99b55
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>