Improve MessageQueue tests for error handling

Add two new test cases to the UnsynchronizedWriteTest suite to verify that the MessageQueue class correctly handles attempts to read more data than is allowed.

Test: atest fmq_unit_tests
Test: atest fmq_test
Bug: b/339169655
Change-Id: Ie4195279a6d817ac1ffd9d2959ebefc18894831a
1 file changed