Validate ringtone URIs before setting am: 7ba175eaeb am: 236f1a0f17 am: 623d966fac

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Settings/+/24956689

Change-Id: Iaa926f8a61ba0c6e4d6511750b3e1dfe83627037
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>