Sync feature support for blockstorage V1 and V2 api.

 * Removed majority of duplicated code between versions.
 * Refactored behaviors to use new StatusProgressionVerifier
   to greatly reduce the time it takes for behaviors to catch
   error-state status progressions. (They now fail on error, or
   invalid state changes instead of naively timeing out.)

Change-Id: I55cd07afa0e2ea7955b763afd97e5fc9e15ce803
Merge "Sync feature support for blockstorage V1 and V2 api."