Adding fuzzers for StoragedService and StoragedPrivateService

- StoragedService and StoragedPrivateService are defined in global
namespace. Moving them to android namespace
- Adding AIDL service fuzzers for both services

Bug: 232439428
Test: adb shell /data/nativetest64/storaged-unit-tests/storaged-unit-tests
Test: m storaged_service_fuzzer && adb sync data && adb shell /data/fuzz/x86_64/storaged_service_fuzzer/storaged_service_fuzzer
Test: m storaged_private_service_fuzzer && adb sync data && adb shell /data/fuzz/x86_64/storaged_private_service_fuzzer/storaged_private_service_fuzzer
Change-Id: Ieb6ff8117f548dd1ef376aab8e6d3dfec9fb06d3