VMware: use storage policy in datastore selection

This is part of the blueprint vmware-spbm-support. This patch adds
storage policy as an additional filter to the datastore selection.
Datastores not matching the storage policy are filtered.

Co-authored-by: Radoslav Gerganov <rgerganov@vmware.com>
Co-authored-by: Gary Kotton <gkotton@vmware.com>

Change-Id: Id934b39614bb5d26e109f6f0f58b033173bfbe70
Merge "VMware: use storage policy in datastore selection"