Fix bug #15115542 Ripple effect is crashing Settings with java.lang.NullPointerException

- for having the tint attribute to be populated you need to have the Theme passed.
This is why Fragment.getActivity().getDrawable(...) should be used instead of
Fragment.getResources().getDrawable(...)

Change-Id: I945eca98e1d73fda3b290a6ababfd1fb41118d8f
diff --git a/src/com/android/settings/SettingsPreferenceFragment.java b/src/com/android/settings/SettingsPreferenceFragment.java
index 9fbdebe..a1f5ecd 100644
--- a/src/com/android/settings/SettingsPreferenceFragment.java
+++ b/src/com/android/settings/SettingsPreferenceFragment.java
@@ -144,7 +144,7 @@
     }
 
     private Drawable getHighlightDrawable() {
-        return getResources().getDrawable(R.drawable.preference_highlight);
+        return getActivity().getDrawable(R.drawable.preference_highlight);
     }
 
     /**