Merge "Explain how to get a tombstone proto." am: 8c8df228 am: 4ab113b8...

Merge "Explain how to get a tombstone proto." am: 8c8df228 am: 4ab113b8 am: a11fd621 am: 9b3927f4

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2215564



Change-Id: Ic18c2b63425ff2de6b4ef90abb3bb5b53c894495
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>