This patch remove the auto trigger post-copy, and add a new libvirt
configuration 'live_migration_completion_action'.
This option determines what actions will be taken against a VM after
``live_migration_completion_timeout`` expires. This option is set to
'abort' action by default, that means the live migrate operation will
be aborted after completion timeout expires. If option is set to
'force_complete', that means will either pause the VM or trigger
post_copy depending on if post copy is enabled and available.
Note that the progress based post-copy triggering from the libvirt
driver will be removed in next patch [1].
[1] Ife89a705892ad96de6d5f8e68b6e4b99063a7512
Change-Id: I0d286d12e588b431df3d94cf2e65d636bcdea2f8
blueprint: live-migration-force-after-timeout
99a075cc94