DO NOT MERGE ANYWHERE Fix UE initiated detach Abnormal case

BUG=31487061

DCSwitch-state machine will not transition to AttachingState
from AttachedState on receiving EVENT_DATA_DETACHED.

Fix is provided by Qualcomm and has been extensively reviewed.
Refer to the bug for additional details.

Change-Id: Ie8e5948c390c7e68b4c39cfa3c821af95deb157e