cherry-pick: Update fontchain_linter.py to be compatible with Compat font

Bug: 186700756
Test: m fontchain_lint

Merged-in: Ibfe33f29f3db998fdc0db1bbf35851841ca73d9a
Change-Id: Icfd3a8ee9e9bb4d877d721044a905ee7ecc6ed9a
1 file changed