Move some inner static class to top class in new package

This change introduces new package com.android.inputmethod.keyboard
which hosts keyboard related classes.

Also adds missing @Override and @SuppressWarning("unused") annotation

Change-Id: I0317f5cfa317e13f3c77815f48ffc69b5d1ade05
diff --git a/java/res/values/styles.xml b/java/res/values/styles.xml
index 02d21b4..130714f 100644
--- a/java/res/values/styles.xml
+++ b/java/res/values/styles.xml
@@ -15,7 +15,7 @@
 -->
 
 <resources>
-    <style name="BaseKeyboardView">
+    <style name="KeyboardView">
         <item name="android:background">@drawable/keyboard_background</item>
 
         <item name="keyBackground">@drawable/btn_keyboard_key</item>