Adding fuzz_config in rust_defaults

rust_defaults doesn't recognize fuzz_config properties unlike
cc_defaults. Adding fuzz_config properties to rust defaults.

Test: m parcel_fuzzer_rs && adb shell data/fuzz/x86_64/parcel_fuzzer_rs/parcel_fuzzer_rs
Bug: 296305888
Change-Id: I4ae4f9d3776e3a6340fce6e3095a00931677cbe7