Filter Alias which points non-existing font family name

The FontFamily will be removed if none of font files exist on the
device.

Bug: 192479819
Test: atest FontListParserTest
Change-Id: I36f6476fe37bc04ec8737936747385c63908d651
(cherry picked from commit 691cfe8818513e576300cdb963a65341984659c4)
2 files changed