Disable concurrent MQ in SysUI

Address reports of barrier message leak.
Will undo this once we ship the upcoming DeliQueue algorithm.

Bug: 436941592
Bug: 436942235
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f59f251d9528d0ae1242d2c48c7d22e6afe0127e)
Merged-In: I4185eefaa5ceab337ddf3a476770ed863d0ef751
Change-Id: I4185eefaa5ceab337ddf3a476770ed863d0ef751

Change-Id: I283c32d166321f567c2a359be0aa542ee1f1140a