[PK Setting] Add null check on NewKeyboardSettingUtils.getInputDevice()

return null if InputDeviceIdentifier is null in getInputDevice.

Test: n/a
Bug: 307109888
Change-Id: Ie2f951d97e0ff66833d74170e625fb0368d6de42

src/com/android/settings/inputmethod/NewKeyboardSettingsUtils.java

@@ -110,7 +110,8 @@ public class NewKeyboardSettingsUtils {
     }
 
     static InputDevice getInputDevice(InputManager im, InputDeviceIdentifier identifier) {
-        return im.getInputDeviceByDescriptor(identifier.getDescriptor());
+        return identifier == null ? null : im.getInputDeviceByDescriptor(
+                identifier.getDescriptor());
     }
 
     static KeyboardLayout[] getKeyboardLayouts(InputManager inputManager, int userId,