Re-enable test_failed_change_at_head_with_queue

This ensures the state of the queue, not the builds, so we cannot use
FakeBuild.hasChanges. This is unique, so there doesn't seem to be any
need to genericize the operation.

Change-Id: I13532f4038170ac4539f1d0131dd4a06e6ffd8ac
Story: 2000773
Task: 3377
1 file changed