Parcel: service fuzzing mode

In service fuzzing mode, we disable logs in the core
Parcel code and also limit some API checks.

This increases fuzzer efficiency (~2x or more, ignoring
service-specific inefficiencies) just due to bypassing
the 'mixing copies of libbinder' check, which isn't
critical for fuzzing.

Bug: N/A
Test: manual, diffing strace outputs
Change-Id: I4952b3ab5f55f27f33d5124e39541fdd40143971