[Android] Remove unnecessary attributes from the ViewPager layout XML file.

Source/Android/res/layout/prefs_viewpager.xml

@@ -1,6 +1,5 @@
-<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
+<android.support.v4.view.ViewPager 
+    xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/pager"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    tools:context=".PrefsActivity" />
+    android:layout_height="match_parent" />