Do not intercept LANGUAGE_SWITCH in the framework layer

Currently, the LANGUAGE_SWITCH key code will be used to switch the keyboard layout in PhoneWindowManager; however, this prevents IMEs like GBoard from switching the language, which is the intended behavior.

Test: manual
Bug: 240865722
Signed-off-by: LiZhihong <lizh52@lenovo.corp-partner.google.com>
Change-Id: If5fcf65522a0a08f89e5594b6fc9576c2a77d0cb