Merge "Add proto tombstones to Dropbox." am: 3361ca6c56 am: 093e8d266a

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1590892

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I828d8f22f643513cce2841470e272cc22231b138