swipeTracker: Set up 1fg drag gesture in capture phase

This should be handled in the capture phase so containers setting
up the drag gesture have an opportunity to handle events from children.
This also follows what the 3fg swipe gesture does.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2278>

js/ui/swipeTracker.js

@@ -503,7 +503,7 @@ var SwipeTracker = GObject.registerClass({
             this.bind_property('orientation', this._dragGesture, 'orientation',
                 GObject.BindingFlags.SYNC_CREATE);
             this.bind_property('distance', this._dragGesture, 'distance', 0);
-            actor.add_action(this._dragGesture);
+            actor.add_action_full('drag', Clutter.EventPhase.CAPTURE, this._dragGesture);
         } else {
             this._dragGesture = null;
         }