Adds support for generating app code to allow java mainline modules to
call the StatsLog.writeRaw public API. Supports primitives, enums,
attribution chains, MODE_BYTES. Does not support key value pairs,
worksource methods (because worksource uses hidden apis in the
worksource object).
Test: manually tested atom logging from DocumentsUI
Test: existing autogenerated code is not modified
Test: cts will follow
Bug: 126134616
Change-Id: Ia321cf2d9952e3875ed0c7a28db1f4113711513f
2910d5aa16