Add --supportQ flag to java StatsLog codegen

Add support to generate Q schema code generation only for modules that
ship to Q.

Bug: 145606209
Test: m
Test: flashes successfully
Test: adb logcat "*:S statsd:*"
Change-Id: I978ac321415f1e8d76e4ec73445894965845aaea
Merged-In: I978ac321415f1e8d76e4ec73445894965845aaea