Merge "Add proto tombstones to Dropbox." am: 3361ca6c56 am: 093e8d266a am: a1b7331722 am: c78b8d8dac

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I97c11ec415ea6e8d1cb1b7f2be0ce4bfcaa951ca