Add emoji icon and code as a groundwork

The emoji switching key icon asset should be updated. The icons in
this change are just borrowed from Hangout.

Bug: 10179862
Bug: 6370846
Change-Id: Icea26d2cf2ac6a6df9beb4c98f646dbe309bdcd9
diff --git a/java/res/values/keyboard-icons-black.xml b/java/res/values/keyboard-icons-black.xml
index e9c5733..c1b1b65 100644
--- a/java/res/values/keyboard-icons-black.xml
+++ b/java/res/values/keyboard-icons-black.xml
@@ -39,5 +39,6 @@
         <!-- TODO: Needs dedicated black theme ZWNJ and ZWJ icons -->
         <item name="iconZwnjKey">@drawable/sym_keyboard_zwnj_holo</item>
         <item name="iconZwjKey">@drawable/sym_keyboard_zwj_holo</item>
+        <item name="iconEmojiKey">@drawable/ic_emoji_light</item>
     </style>
 </resources>