Fix security vulnerability when register phone accounts. am: 833dd8480a am: 581e22326e am: a0d2781092 am: 275debd2b6

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/20028194

Change-Id: Iebea286319202fc163ff973441deaeab4d8f95ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>