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

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

Change-Id: I3b378018ca0855ef1dad1964cf4b1418e6dcba63
Signed-off-by: Automerger Merge Worker <[email protected]>