When clustered Data ONTAP clones a flexvol, the clone gets the
NFS export policy of its parent. Manila expects the clone to be
independent of its parent, so it should be given its own export
policy. This isn't happening in the Kilo cDOT driver.
Change-Id: I5067fc5729bec62de19d1aeaed7ed60d2224e498
Closes-Bug: #1446369
(cherry picked from commit b907ca09f1)