restapi: REST api for stop rebalance of volume

REST api for stop rebalance of volume

Change-Id: I12c4d83e2c7e8c89dd9f820bc26ef369a4cb0490
Signed-off-by: Shubhendu Tripathi <shtripat@redhat.com>
Signed-off-by: Timothy Asir <tjeyasin@redhat.com>