Adding linter for checking license (and copyright)  header in java/kotlin files

Fixes: 302679200
Test: MissingApacheLicenseDetectorTest
Test: run `m SYSTEM_UI_CORE_PATH/lint-report.html` and see legit license warnings/errors
Change-Id: I8c79e74f6a171964b30b93e029eeef0ef72a045c
4 files changed