Extend DPAD support.

Allows the hardware DPAD to control more of the UI.

Closes #4989
// FREEBIE

res/layout/conversation_list_item_view.xml

@@ -4,6 +4,9 @@
         xmlns:app="http://schemas.android.com/apk/res-auto"
         xmlns:tools="http://schemas.android.com/tools"
         android:layout_width="match_parent"
+        android:focusable="true"
+        android:nextFocusRight="@+id/fab"
+        android:nextFocusLeft="@+id/container"
         android:layout_height="70dp">
 
     <org.thoughtcrime.securesms.components.AvatarImageView