CLOUDSTACK-8107. Failed to create snapshot from volume when the task is performed repeatedly in zone wide primary Storage.
While taking a snapshot of a volume, CS chooses the endpoint to perform backup snapshot operation by selecting any host that has the storage containing the volume mounted on it.
Instead, if the volume is attached to a VM, the endpoint chosen by CS should be the host that contains the VM.

(cherry picked from commit a75a43137316a60b20760aa5015d97f55520fd16)