Remove dumpstate error race condition

Removes the race condition between the dumpstate binder service
death recipient and the dumpstate listener error callback. This
is done by adding a small wait when the death recipient is
invoked. This ensures that the caller of the Bugreport API does
not erroneously receive an incorrect runtime error callback.

Alters internal tests to account for this new delay.

Bug: 147703592
Test: atest BugreportManagerTest
Test: Manual. Take bugreport, ensure that the death recipient
      does not send an error callback when dumpstate finishes
      successfully, or fails and exits. Test error case by
      manually invoking signalErrorAndExit in DumpstateService.
Change-Id: I8c5b14c88502f0cf4f4f0e5c41d90d6065bfd1d4