Require MODIFY_PHONE_STATE for preferred TTY mode am: 266f2436b9 am: ffef8f58e4

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/12673305

Change-Id: Iebfc038160e226a1a2652aed037fe7f36cdd0ba5