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

services/java/com/android/server/wm/WindowManagerService.java

@@ -6973,7 +6973,7 @@ boolean computeScreenConfigurationLocked(Configuration config) {
             // Determine whether a hard keyboard is available and enabled.
             boolean hardKeyboardAvailable = false;
             if (!mForceDisableHardwareKeyboard) {
-                mHardKeyboardAvailable = config.keyboard != Configuration.KEYBOARD_NOKEYS;
+                hardKeyboardAvailable = config.keyboard != Configuration.KEYBOARD_NOKEYS;
             }
             if (hardKeyboardAvailable != mHardKeyboardAvailable) {
                 mHardKeyboardAvailable = hardKeyboardAvailable;