Fuzzer for default vibrator service.

As an example for a fuzzer of an AIDL service.

Bug: 224646709
Test: run fuzzer for a few minutes (doesn't get very
    deep in the fuzzer - will follow-up with a dictionary
    or a corpus if the fuzzer can't get past the header
    and interface token)
Change-Id: Iac02a1f02500a0098d67823ac22de1706778927b