Convert much of f/b/data/fonts/Android.mk to Android.bp

The Serif symlinks haven't been used since 2014, so I removed them.

Test: treehugger
Test: m fonts.xml DroidSansMono.ttf AndroidClock.ttf, ensure same installed files
Change-Id: I496498e0debac37f5fff4b9e046813e6b2694fd5