DO NOT MERGE Make sample IME aware of language switching

This CL demonstrates how the new language switching functionality
should work by using the SoftKeyboard sample.

BUG: 15267645
Change-Id: I18ab25a0784979fe6028b97a22ff02bfd502d506
(cherry picked from commit 88838a30afcfff443bc4335b65a1dd20c07f9ff3)
9 files changed