Don't force concurrent MQ in Robolectric tests

Robolectric is not yet updated to be robust to new MQ.
We only updated Test{,able}Looper and Espresso so far.

Bug: 379472827
Flag: android.os.force_concurrent_message_queue
Change-Id: I2a03c9e5753820f6efb648a40d3392c3e4135f53