Do not initialize Typeface on font file deletion

When attempting to remove a font file from the font cache, first make
sure that Typeface has previously been initialized. If it hasn't, do
nothing as initializing Typeface then would likely cause a crash.

Bug: 123725544
Test: checked manually from Studio
Change-Id: I18184cbf44552306a8413d6e2aaf4dd5fb2c86b9