title: constraint layout with percentage Guideline dont work in wrap_content
body: <p>hi guys i want a imageview with the height of 30% of the screen how should i do it? this is my code but its not working when i change the constraintLayout height to match parent it takes all the screen and when i set it to wrap_content now i have nothing in screen
  this is my Code: </p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"&gt;
  
      &lt;android.support.v7.widget.AppCompatImageView
          android:layout_width="match_parent"
          android:layout_height="0dp"
          app:layout_constraintBottom_toTopOf="@+id/guideline1"
          app:layout_constraintTop_toTopOf="parent"
          app:srcCompat="@drawable/pic" /&gt;
  
      &lt;android.support.constraint.Guideline
          android:id="@+id/guideline1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:orientation="horizontal"
          app:layout_constraintGuide_percent="0.25"/&gt;
  &lt;/android.support.constraint.ConstraintLayout&gt;
  </code></pre>
  
  <p>i want to use it on recyclerview when i set the height to match parent this is how become <a href="https://i.stack.imgur.com/ppn5T.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ppn5T.png" alt="enter image description here"></a> its a lot of empty space below</p>
  
  <p><strong><a href="https://i.stack.imgur.com/GWsN7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GWsN7.jpg" alt="UPDATE"></a></strong></p>