Make InputReader test components thread safe

This changes all assert*() methods in the following classes to enable
waiting for the assertion to be true:
- FakeInputReaderPolicy
- FakeEventHub
- FakeInputMapper
- TestInputListener

This change should make InputReader robust to being run on another
thread.

Bug: 130819454
Test: atest inputflinger_tests # on crosshatch
Change-Id: I9619109e3377eb706d71fb34d525bd3bdc4ef81a