title: Cannot add views to ComposeView; only Compose content is supported
body: <p>I'm attempting to add Jetpack Compose composables to my xml file in a fragment.</p>
  <p>When I try to run it on a device I'm getting an error:
  <code>Cannot add views to ComposeView; only Compose content is supported</code></p>
  <h2>Fragment:</h2>
  <pre><code>class ComposeFragment : Fragment() {
  
      override fun onCreateView(
          inflater: LayoutInflater,
          container: ViewGroup?,
          savedInstanceState: Bundle?
      ): View? {
          val view = inflater.inflate(
              R.layout.activity_main, container, false
          )
          view.findViewById&lt;ComposeView&gt;(R.id.compose_view).setContent {
              Column(
                  modifier = Modifier
                      .border(border = BorderStroke(1.dp, Color.Black))
                      .padding(16.dp)
              ) {
  
                  Text(&quot;THIS IS A COMPOSABLE INSIDE THE FRAGMENT XML&quot;)
                  Spacer(modifier = Modifier.padding(10.dp))
                  CircularProgressIndicator()
                  Spacer(modifier = Modifier.padding(10.dp))
                  Text(&quot;NEAT&quot;)
                  Spacer(modifier = Modifier.padding(10.dp))
  
              }
          }
  
          return view
      }
  
  }
  </code></pre>
  <h2>activity_main.xml:</h2>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;RelativeLayout
      xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
      android:layout_width=&quot;match_parent&quot;
      android:layout_height=&quot;match_parent&quot;&gt;
  
      &lt;androidx.fragment.app.FragmentContainerView
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;match_parent&quot;
          android:id=&quot;@+id/main_container&quot;
          /&gt;
  
      &lt;androidx.compose.ui.platform.ComposeView
          android:id=&quot;@+id/compose_view&quot;
          android:layout_width=&quot;wrap_content&quot;
          android:layout_height=&quot;wrap_content&quot;
          /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  <h2>MainActivity.kt:</h2>
  <pre><code>open class MainActivity : AppCompatActivity() {
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
  
          setContentView(R.layout.activity_main)
  
          supportFragmentManager.beginTransaction()
              .replace(R.id.compose_view, ComposeFragment())
              .commit()
      }
  }
  </code></pre>
  <p>I'm not really sure what this error means or how to address it.  I can't find this error anywhere by googling.</p>