fix: raise elevation on the attachment buttons

app/src/main/res/layout/activity_conversation_v2.xml

@@ -52,6 +52,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginStart="@dimen/small_spacing"
+        android:elevation="8dp"
         android:layout_alignParentStart="true"
         android:layout_alignParentBottom="true"
         android:layout_marginBottom="60dp"