Merge "Use backstop timeouts on asynchronous countdown during preflight" into nyc-dev
am: 210f2ff198

* commit '210f2ff19808ce6b261a84596bf141909ecb381c':
  Use backstop timeouts on asynchronous countdown during preflight

Change-Id: I6839fa3658cdd1fe3210761f1cb6cd65453bf8a6