Add app_bar.xml

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

+<?xml version="1.0" encoding="utf-8"?>
+<android.support.design.widget.AppBarLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@color/colorPrimary"
+    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
+
+    <android.support.v7.widget.Toolbar
+        android:id="@+id/toolbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        app:layout_scrollFlags="scroll|enterAlways"
+        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
+        app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
+
+</android.support.design.widget.AppBarLayout>
\ No newline at end of file