Add backend for LOCAL_FUZZ_DATA for cc_fuzz corpus/dict.

Adds the backend makefile parser for the LOCAL_FUZZ_DATA vars generated
by the cc_fuzz target.

Bug: 141026328
Test: m example_fuzzer, fuzz target should have adjacent corpus/dict
files.

Change-Id: Ide2c34318f11be132992650ce5cc1fd27895915c