DeliQueue check for a live barrier when enqueuing messages

If we see that the message comes before the barrier we need to wake
the looper thread to process it.

Test: atest MessageQueueTest
Bug: 421623328
Flag: EXEMPT new data structure isn't used yet; usages will be flagged.
Change-Id: I2d0e155fcde09010e72818f128ff4d78576d233b