Adds constraints.

app/src/main/res/layout/fragment_admin_panel_web_view.xml

@@ -9,7 +9,11 @@
     <WebView
         android:id="@+id/web_view"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="match_parent"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
 
     <com.wang.avi.AVLoadingIndicatorView
         android:id="@+id/view_loading"