title: Is it possible to animate groups visibility with MotionLayout?
body: <p>I'm trying to make an animation with MotionLayout, and I need to hide some elements.
  I tested visibility attribute in an individual element and it works, but to make the XML shorter I would like to be able to specify just a group (from the ConstraintLayout helpers) containing all this elements</p>
  
  <p>Something like this</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"&gt;
  
      &lt;Transition
          app:constraintSetStart="@id/start"
          app:constraintSetEnd="@id/end"
  
          app:duration="300"&gt;
  
          &lt;OnSwipe
              app:touchAnchorId="@id/details_group"
              app:touchAnchorSide="bottom"
              app:dragDirection="dragDown"
              /&gt;
  
      &lt;/Transition&gt;
  
      &lt;ConstraintSet
          android:id="@+id/start"&gt;
  
          &lt;Constraint
              android:id="@+id/details_group"
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:visibility="gone"
              app:constraint_referenced_ids="detail_value_topl,detail_icon_topl,detail_value_topr" /&gt;
  
      &lt;/ConstraintSet&gt;
  
      &lt;ConstraintSet
          android:id="@+id/end"&gt;
  
          &lt;Constraint
              android:id="@+id/details_group"
              android:layout_width="0dp"
              android:layout_height="0dp"
              android:visibility="visible"
              app:constraint_referenced_ids="detail_value_topl,detail_icon_topl,detail_value_topr" /&gt;
  
      &lt;/ConstraintSet&gt;
  
  &lt;/MotionScene&gt;
  </code></pre>
  
  <p>But it doesn't work, any idea how to make it work ?</p>
  
  <p>Also, I would prefer <strong>not to use alpha</strong>, since all constraints are set so that when they are gone the container resizes</p>