Bug 1233412 - Fix GeckoPref crashes on Jelly Bean due to theme missing colorAccent. r=sebastian

--HG--
extra : transplant_source : %BC7%9E%DD%13%F2%DB%87%E9%DFp%F29%B1%F4%E4Tgm%C4

mobile/android/base/resources/values/themes.xml

@@ -105,6 +105,8 @@
 
     <style name="Gecko.Preferences" parent="GeckoPreferencesBase">
         <item name="floatingHintEditTextStyle">@style/FloatingHintEditText</item>
+        <!-- This fixed bug 1233412 (Crash in GeckoPrefs due to missing colorAccent in JB) -->
+        <item name="colorAccent">@color/action_orange</item>
     </style>
 
     <!-- Make an activity appear like an overlay. -->