Added Backup/Restore validations

Added checks for backup-create API call to ensure
datastore supports backup strategy
Also for trove-create API call (when restoring from backup)
added checks to ensure that datastore version of backup
being restored matches with datastore version of
instance being created

Change-Id: I9f9cf76ce3d2533612515e6382a184e955e09a32
Closes-Bug: #1285876
Merge "Added Backup/Restore validations"