surfaceflinger_fuzzer: Bug Fix

Resolved Abort due to improper message handling. Handled the messages scheduled via postMessage() in fuzzer.

exec/s: 40
Test: ./surfaceflinger_fuzzer clusterfuzz-testcase-minimized-surfaceflinger_fuzzer-5382002773655552
Test: ./surfaceflinger_fuzzer clusterfuzz-testcase-minimized-surfaceflinger_fuzzer-5163836271296512
Bug: 291500072
Bug: 294639179

Change-Id: I874f95bfe92de7e8adc462b66867429c2d8834b5
1 file changed