SkFontMgr_Android refactoring

Change-Id: If3d9a9933675b7e2528859ba7300e60d5f029f8d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/919077
Commit-Queue: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
5 files changed