Drop the *.create.start notification for Neutron

Based on current implement, there is no resource id assigned
when *.create.start notification sending, so Ceilometer will
run into KeyError. So this fix will drop the *.create.start
notification because the meter can't be linked to correct
resource. Besides the info can be collected by *.create.end.

Fixes bug 1222737

Change-Id: I785ae1ca1383dc5f9afbf2ab072a6e1efc582606
Merge "Drop the *.create.start notification for Neutron"