Add inputflinger blockingQueue/classifier fuzzers

This CL aims to add libfuzzer fuzzers to inputflinger, to test the
BlockingQueue and InputClassifier objects.

Test: Each fuzzer was tested on a Pixel 3a for a few million
      iterations to ensure stability. Executions/sec average about
      500 for the BlockingQueue fuzzer, and ~2000-2500 for the
      InputClassifier fuzzers.
Signed-off-by: Michael Ensing <michael.ensing@leviathansecurity.com>
Change-Id: If48e5ddbe3066800da88216882ffbbf417dc0d2c