Merge "Call Forward Setting preference is disabled when setting an empty number" am: 9ef702e8d3 am: 6efd47d473 am: 2da6df523c

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/2461895

Change-Id: Ifde19e4718497aa6542bd7224b0074798e0383e1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>