Add key layout for Nintendo Switch controller

The controller for Nintendo Switch is currently missing a key layout,
and the resulting codes are incorrect. Provide the appropriate map here.

Also, update some button mappings for the Xbox 360 controller.

Bug: 135136477
Test: Tested using "gamepad tester". CTS test will be added in a future
release. Tested using custom app.

Change-Id: I1ffcabdcc11aa83316c483ea49cb10fc85f6264f