core: update isInitialized in the same TX

a part of a CreateVmVDSCommand is to upadate the isInitialized db
column.
Trying to set isInitialized with a new transaction will always
fail since the current (parent)  TX is locking vm_static already by
other pending commits that have been made.

Change-Id: I65557ca425eebd91c78ce4a4001e4ba4532b56d6
Bug-Url: https://bugzilla.redhat.com/890953
Signed-off-by: Roy Golan <rgolan@redhat.com>