[locales] refactor android specific locale variables

This CL changes the name of two variables in build/config/locales.gni.

  - android_chrome_omitted_locales -> android_apk_omitted_locales
    - These locales used to be omitted on all Android builds.  They are
    now only omitted on APK builds.
  - android_only_chrome_locales -> android_bundle_only_locales
    - These locales are only used on android bundles.

This CL also fixes an error in tools/locale_tool.py to work with the
new variables.

Change-Id: Id6f6dddaf415c7be195a95c688227d0ace95ec75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042137
Commit-Queue: Trevor  Perrier <perrier@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Megan Jablonski <megjablon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739673}

• build/config/locales.gni[diff]
• build/locale_tool.py[diff]
• chromecast/chromecast.gni[diff]