Add desc scroll

app/src/leanback/res/layout/dialog_desc.xml

@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
-<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fillViewport="true">
+
+    <TextView
         android:id="@+id/text"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
@@ -8,3 +13,5 @@
         android:padding="16dp"
         android:textColor="@color/grey_800"
         android:textSize="16sp" />
+
+</androidx.core.widget.NestedScrollView>