Added downloading spinner

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

@@ -62,6 +62,17 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/tvNoInternetBody" />
 
+    <eu.faircode.email.ContentLoadingProgressBar
+        android:id="@+id/pbDownloading"
+        style="@style/Base.Widget.AppCompat.ProgressBar"
+        android:layout_width="24dp"
+        android:layout_height="24dp"
+        android:indeterminate="true"
+        app:layout_constraintBottom_toBottomOf="@id/tvDownloading"
+        app:layout_constraintEnd_toEndOf="@id/tvDownloading"
+        app:layout_constraintStart_toStartOf="@id/tvDownloading"
+        app:layout_constraintTop_toTopOf="@id/tvDownloading" />
+
     <ImageButton
         android:id="@+id/ibDownloading"
         android:layout_width="wrap_content"
@@ -153,5 +164,5 @@
         android:id="@+id/grpDownloading"
         android:layout_width="0dp"
         android:layout_height="0dp"
-        app:constraint_referenced_ids="tvDownloading,ibDownloading" />
+        app:constraint_referenced_ids="tvDownloading,pbDownloading,ibDownloading" />
 </androidx.constraintlayout.widget.ConstraintLayout>