Add a helper script to apply lint fixes

See tools/lint/fix/README.md

Add tools/lint/fix/lint_fix.py.  A helper
script for developers that want to use Android Lint's
quickfix functionality to refactor platform code.

Bug: 157626959
Test: This tool was used to generate automated CLs via lint fixes, for
example ag/19322033

Change-Id: Ic36bfb0cda095d131d7af202d1445b2d9ca6db4e