Revert "Remove MessageQueue reflection from TestLooper"

This reverts commit ef730976.

Reason for revert: `Build.VERSION.SDK_INT >= Build.VERSION_CODES.BAKLAVA;` is a ticking bomb for the SDK team. Can you please hold off on this assumption until we've finalized the SDK and bumped the SDK_INT for all relevant configurations (next, trunk and trunk-staging). (I bumped it to 36 for trunk-staging in ag/31522509 which triggered this code to be active and (probably) led to b/393534402)

Change-Id: I9e6279f5d4845469cd29e47501da3e8546fc71d2