update mvvm

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

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    tools:context=".activity.main.MainActivity">
+
+    <data>
+
+    </data>
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <FrameLayout
+            android:id="@+id/content"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+</layout>