Handle IllegalArgumentException for unregistering the receiver

It may be that the test doesn't register the receiver before failing. In
this case we catch the exception thrown when unregistering is attempted.
We apply this in tearDown().

Additionally, we reorder the calls so starting the activity happens after
registering. This means registering should successfully complete more
often (starting the activity appears to be more flaky)

Test: atest AccessibilityDisplayProxyTest
Bug: 314297480
Change-Id: I82b10a6ebdb32a508fc62eeed6794cff542cbc5c
1 file changed