Add tests for asan-libfuzzer and msan-libfuzzer

[tengpengli]

Expected Behavior

The fuzzing examples under examples need more tests, the behavior of the test under config msan-libfuzzer and asan-libfuzzer should be different.

Actual Behavior

The typo happened in https://github.com/googleinterns/bazel-rules-fuzzing/pull/56#discussion_r470059357 doesn't result in any error, which means more tests are needed.