Merge "Fix home/back buttons flow in PreferenceActivity."

import android.util.TypedValue;

import android.util.Xml;

import android.view.LayoutInflater;

import android.view.MenuItem;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

 * however vary; currently there are two major approaches it may take:

 *

 * <ul>

 * <li>On a small screen it may display only the headers as a single list

 * when first launched.  Selecting one of the header items will re-launch

 * the activity with it only showing the PreferenceFragment of that header.

 * <li>On a large screen in may display both the headers and current

 * PreferenceFragment together as panes.  Selecting a header item switches

 * to showing the correct PreferenceFragment for that item.

 * <li>On a small screen it may display only the headers as a single list when first launched.

 * Selecting one of the header items will only show the PreferenceFragment of that header (on

 * Android N and lower a new Activity is launched).

 * <li>On a large screen in may display both the headers and current PreferenceFragment together as

 * panes. Selecting a header item switches to showing the correct PreferenceFragment for that item.

 * </ul>

 *

 * <p>Subclasses of PreferenceActivity should implement

        };

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        if (item.getItemId() == android.R.id.home) {

            // Override home navigation button to call onBackPressed (b/35152749).

            onBackPressed();

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    @Override

    protected void onCreate(@Nullable Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);