Validate ringtone URIs before setting am: 7ba175eaeb am: 236f1a0f17 am: 623d966fac am: a4a9b9f0e7 am: fa932686c5 am: 179f53c651 am: b36b1dab96

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

Change-Id: Iaa3e61923eddada09aa19b61428ee60630b57cf1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>