[Panlingual] Implement entries of Panlingual in settings UI part.

 - Path 1 : System -> Language & Input -> App Languages -> per app
 language
 - path 2 : System -> Apps -> App Info -> per app language
 Video: https://screencast.googleplex.com/cast/NjUyNTUzMDY0MTc5MzAyNHxjNTg2MzMwYS0yOA

Bug: 206854105
Test: local test pass
Test: atest pass

Change-Id: Ic06fa4f0c6ec68680eb828032b6e3f479b412dc4
14 files changed