Add a Toolbar to an Activity

public class MyActivity extends AppCompatActivity {
  // ...
}

AndroidManifest.xml

<application
    android:theme="@style/Theme.AppCompat.Light.NoActionBar"
    />
<android.support.v7.widget.Toolbar
   android:id="@+id/my_toolbar"
   android:layout_width="match_parent"
   android:layout_height="?attr/actionBarSize"
   android:background="?attr/colorPrimary"
   android:elevation="4dp"
   android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
   app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
    Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
    setSupportActionBar(myToolbar);
    }

Update 11/20/2017

This seems a better approach :
Note that this code generate Toolbar with white text and icons

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayoutSelectLabTest"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbarSelectLabTest"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

References
https://developer.android.com/training/appbar/setting-up.html
https://stackoverflow.com/questions/30178727/set-menu-overflow-icon-to-be-white