Fix Locale.getDisplayName.

- Don't append the country instead of the script.
- Ensure that there's a "," separating the country and
  the script.
- Add missing tests for Locale#getDisplayName when scripts
  and variants are present.

bug: 13790258
Change-Id: I7a3f3db73879755fa8159f94a378bc585c779cc2
2 files changed