fix(Chat/Message): force `height` attribute on completed event

tests/ui/modules/Linphone/Chat/Message.qml

@@ -40,4 +40,9 @@ Item {
 
     anchors.left: rectangle.right
   }
+
+  // In some case the initial `implicitHeight`
+  // state is incorrect. This line is a workaround that forces
+  // the `height` attribute.
+  Component.onCompleted: height = text.contentHeight + text.padding * 2
 }