core: NPE when executing RunVmOnceCommand from rest

RunVmOnceCommand -> reportCompleted:
'getParameters().getRunAndPause()' can be null when starting
a VM from the rest-api. Hence, an NPE is thrown.

['runAndPause' variable has been changed to Boolean in:
Ib1fe46a9946f7914095310ddac9ab1a9e5a6564b]

Change-Id: Id9a1b2b290c2c642ed3f1891582ac679a3a336c9
Bug-Url: https://bugzilla.redhat.com/974999
Signed-off-by: Daniel Erez <derez@redhat.com>