CA-91927: Reduce the frequency of VM.allowed_operations updates.
CA-91927: Reduce the frequency of VM.allowed_operations updates.

When xapi receives a VM update from xenopsd, allowed_operations should
only be updated if a VM field which could affect the allowed_operations
was changed.

Signed-off-by: John Else <37b74501daa612e48fea94f9846ed4ddeb6a8f07@citrix.com>

djs55/xcp-rrdd,johnelse/xcp-rrdd,simonjbeaumont/xcp-rrdd,johnelse/xcp-rrdd,djs55/xcp-rrdd,sharady/xcp-networkd,robhoes/squeezed,koushikcgit/xcp-networkd,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-networkd,djs55/squeezed,djs55/xcp-networkd,koushikcgit/xcp-rrdd