enforce stricter rules when registering phoneAccounts am: f07776bc42

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/21320003

Change-Id: Ib9b5d7cc92297eae0314fdb7f94593b38e531d46
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>