This CL adds functionality to trigger the "Physical keyboard"
settings screen via an intent.
Bug: 26943892
Change-Id: Ib4a0be38f94f83672501d5312079d132b2ab717d
1. Introduces new UI components as per the new flow
2. Temporarily disables components in the old flow that are to be
replaced by the new flow. This is done so we can neatly revert
to the old flow if there are issues with the new flow
3. AvailableVirtualKeyboardActivity now responds to
android.settings.INPUT_METHOD_SETTINGS intents instead of
InputMethodAndLanguageSettingsActivity
Bug: 25752812
Change-Id: I728d7ee185827ed328c16cb7abce244557a26518
