Add emoji categories and backspace assets

app/src/main/res/drawable/ic_backspace_black_24dp.xml

+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportHeight="24"
+    android:viewportWidth="24">
+
+    <path android:pathData="M0,0 L24,0 L24,24 L0,24 Z" />
+    <path
+        android:fillColor="#000000"
+        android:pathData="M22,3 L7,3 C6.31,3,5.77,3.35,5.41,3.88 L0,12 L5.41,20.11
+C5.77,20.64,6.31,21,7,21 L22,21 C23.1,21,24,20.1,24,19 L24,5 C24,3.9,23.1,3,22,3
+Z M19,15.59 L17.59,17 L14,13.41 L10.41,17 L9,15.59 L12.59,12 L9,8.41 L10.41,7
+L14,10.59 L17.59,7 L19,8.41 L15.41,12 L19,15.59 Z" />
+</vector>
\ No newline at end of file

app/src/main/res/layout/emoji_picker_tab.xml

 <?xml version="1.0" encoding="utf-8"?>
-<TextView xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/text"
+<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/image_category"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:background="@color/whitesmoke"

app/src/main/res/menu/message_actions.xml

@@ -24,7 +24,7 @@
 
         <!--<item-->
         <!--android:id="@+id/action_menu_msg_share"-->
-        <!--android:icon="@drawable/ic_share_black_24px"-->
+        <!--andrtextIconicon="@drawable/ic_share_black_24px"-->
         <!--android:title="@string/action_msg_share" />-->
 
         <item
@@ -34,7 +34,7 @@
 
         <!--<item-->
         <!--android:id="@+id/action_menu_msg_star"-->
-        <!--android:icon="@drawable/ic_star_black_24px"-->
+        <!--andrtextIconicon="@drawable/ic_star_black_24px"-->
         <!--android:title="@string/action_msg_star" />-->
     </group>