How to achieve a full-screen dialog as described in material guidelines?

Material guidelines describe the behavior of a full-screen dialog.

Full-screen dialog | Dialogs - Material Design

How can I achieve this in practice?

The answer from Boss is correct, but missing the requested action bar as displayed on link in the question.

So, full example below.

Dialog fragment:

public class AKDialogFragment extends DialogFragment {

private static final String TAG = "AKDialogFragment";

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.dialog_ak, container, false);

    Toolbar toolbar = (Toolbar) rootView.findViewById(R.id.toolbar);
    toolbar.setTitle("Dialog title");

    ((AppCompatActivity) getActivity()).setSupportActionBar(toolbar);

    ActionBar actionBar = ((AppCompatActivity) getActivity()).getSupportActionBar();
    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeButtonEnabled(true);
        actionBar.setHomeAsUpIndicator(android.R.drawable.ic_menu_close_clear_cancel);
    }
    setHasOptionsMenu(true);
    return rootView;
}

@NonNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Dialog dialog = super.onCreateDialog(savedInstanceState);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    return dialog;
}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    menu.clear();
    getActivity().getMenuInflater().inflate(R.menu.menu_ak, menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();

    if (id == R.id.action_save) {
        // handle confirmation button click here
        return true;
    } else if (id == android.R.id.home) {
        // handle close button click here
        dismiss();
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

Layout dialog_ak.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">

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

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

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

<LinearLayout
    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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffff"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Your content here"/>

</LinearLayout>

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

Menu menu_ak.xml

<menu 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">
  <item
    android:id="@+id/action_save"
    android:orderInCategory="100"
    android:title="Save"
    app:showAsAction="always"/>
</menu>

Hosting activity must extend AppCompatActivity. Launching dialog is the same as in Boss answer:

FragmentManager fragmentManager = getSupportFragmentManager();
AKDialogFragment newFragment = new AKDialogFragment();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
transaction.add(android.R.id.content, newFragment).addToBackStack(null).commit();

I hope it helps someone.