Fix security vulnerability when register phone accounts. am: ce3216cbde

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/20055816

Change-Id: Ic2d05c23a16ce75b24fbc42708f31530a39ea74f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>