Support ACTION_KEYBOARD_LAYOUT_SETTINGS.

This CL let the Settings app accept
Settings.ACTION_KEYBOARD_LAYOUT_SETTINGS like other activity actions
such as ACTION_INPUT_METHOD_SETTINGS and
ACTION_INPUT_METHOD_SUBTYPE_SETTINGS.

Bug: 25752827
Change-Id: I3244d9af400f9344359c1b5cfc1a5c1d9268ec8c