GitLab

This CL enables selecting the app and translate target languages in
the new detailed language settings on Android.  This feature is all
behind a release flag.

Both settings preferences use the added LanguageItemPreference which
launches the existing AddLanguageFragment on tap to select a language.
Languages options in the AddLanguageFragment are filtered based on what
the language will be used for.

setTargetLanguage is added to the TranslateBridge.

The Advanced Settings section is implemented as an Expandable
Preference Group.  Currently the only preference that works in the
advanced section is the Target Language.

Screenshots can be found here: https://crbug.com/1127531#c5

Bug: 1127531
Change-Id: I18707df2e3736920d1e7a4102b55863b99eb21e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2593923
Commit-Queue: Trevor  Perrier <perrier@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Natalie Chouinard <chouinard@chromium.org>
Reviewed-by: Megan Jablonski <megjablon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842665}