Merge "Remove pre-N db after successful migration" into nyc-dev am: cdb5fcf7b8
am: 8a7414ea55

* commit '8a7414ea5550514920a09183727775ae92608810':
  Remove pre-N db after successful migration

Change-Id: I93e2f2db8b6d23d3d483593317a9e2befd5c22d2