engine: [cleanup] Rename RunMultipleActions to runMultipleActions

Findbugs warning message:
Backend.java:508, NM_METHOD_NAMING_CONVENTION, Priority: Low

The method name
org.ovirt.engine.core.bll.Backend.RunMultipleActions(VdcActionType,
                                                     ArrayList, boolean)
doesn't start with a lower case letter

Methods should be verbs, in mixed case with the first letter lowercase,
with the first letter of each internal word capitalized.

Change-Id: I0bfa0221abc1a533f39ec114238b89dbe437164c
Signed-off-by: Adam Litke <alitke@redhat.com>