input: Add workaround for broken hardware keyboard support

* Add workaround var for devices with broken kernels

Patchset 1 : Stick to android code guidelines

Change-Id: Iefbd2389656f5da7bcaa02337aed1ef48ba9653a

Conflicts:
	core/res/res/values/config.xml
	core/res/res/values/symbols.xml
input: Fix workaround for broken hardware keyboard support

Using a wrong reference to mHardKeyboardAvailable caused device config
to never report physical keyboards.

Change-Id: I9b64e2d89512436c17fa8929464e2b727fba1cf3