Reorganize system font APIs

This CL reorganizes the system font related APIs with following things:
- Move match function from system_fonts.h to new header file.
  The matching logic is not only for system fonts. The custom font or
  custom fallback Typeface can be a target of this matcher.

- Introduce new struct AFontMatcher for keeping matching rules.
  This is for future extensibility. We may add another parameter for
  querying fonts in future.

- Renamce ASystemFont to AFont and moved to new header file.
  This is mainly because for future improvements.
  Currently we don't have any plan for doing this in Q timeline, but the
  matcher object can be used for Java Typeface object via JNI. For
  example, build Typeface in Java and pass down to JNI and query the font
  for the passed Typeface.

Bug: 129559385
Test: TEMPORARY_DISABLE_PATH_RESTRICTIONS=true m ndk-docs
Test: atest CtsGraphicsTestCases:android.graphics.fonts
Change-Id: I6c593d9597b1f1ff71eaea6ecf7992890d635480