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

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

Change-Id: I1f9775f4ecb21616829ee73af9558c2b48705203
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>