Fix state sync logic related to the PAUSED VM state

A VM may get into the paused state not only because the user request
via API calls, but also due to (temporary) external instrumentations.
Before the virt layer can reliably report the reason, we simply ignore
the state discrepancy. In many cases, the VM state will go back to
running after the external instrumentation is done.

Fix bug 1097806.

Change-Id: I8edef45d60fa79d6ddebf7d0438042a7b3986b55
(cherry picked from commit f7fbdeb5672bae7d3bffd6fa76de1ce81fc132bf)
Merge "Fix state sync logic related to the PAUSED VM state" into stable/folsom