Use Context.getSystemService(Class<T>) for InputManager.

This is a mechanical replacement of Context.getSystemService(String)
with Context.getSystemService(Class<T>) when retrieving InputManager.
Note those are bundled code.  Hence we don't need to make sure
Build.VERSION.SDK_INT >= 23.

Change-Id: Iee47e374e1349720e3100bab33ed139e1f47c169
diff --git a/packages/SystemUI/src/com/android/systemui/keyboard/KeyboardUI.java b/packages/SystemUI/src/com/android/systemui/keyboard/KeyboardUI.java
index 96ee397..d931856 100644
--- a/packages/SystemUI/src/com/android/systemui/keyboard/KeyboardUI.java
+++ b/packages/SystemUI/src/com/android/systemui/keyboard/KeyboardUI.java
@@ -180,7 +180,7 @@
         mProfileManager = bluetoothManager.getProfileManager();
         bluetoothManager.getEventManager().registerCallback(new BluetoothCallbackHandler());
 
-        InputManager im = (InputManager) context.getSystemService(Context.INPUT_SERVICE);
+        InputManager im = context.getSystemService(InputManager.class);
         im.registerOnTabletModeChangedListener(this, mHandler);
         mInTabletMode = im.isInTabletMode();