Add support for switching between multiple keyboard layouts.

Also show a notification when an external keyboard is connected
and does not have a keyboard layout selected yet.

Bug: 6405203
Change-Id: Id0ac6d83b3b381f8a236b2244a04c9acb203db3c
diff --git a/data/keyboards/Generic.kcm b/data/keyboards/Generic.kcm
index 544076f..782a701 100644
--- a/data/keyboards/Generic.kcm
+++ b/data/keyboards/Generic.kcm
@@ -252,6 +252,7 @@
     label:                              ' '
     base:                               ' '
     alt, meta:                          fallback SEARCH
+    ctrl:                               fallback LANGUAGE_SWITCH
 }
 
 key ENTER {