Allow to hide Expanded Desktop (1/2)

	From ParanoidAndroid
	https://github.com/ParanoidAndroid/android_packages_apps_Settings/commit/494136082e21857fc78b370c9484bb13f2374991

	Allows a option in the power menu settings to show the expanded desktop feature.

        With thanks to Paul Beeler for much rework.

        Patch set 1: Initial revision.

        Patch set 2: Change tabs to spaces in commit message.

        Patch set 3: Add xml overlay to disable feature by default.

                     Feature can be enabled by device maintainers adding a device overlay.

                     E.g. add the following line to
                     device/<manufacturer>/<product>/overlay/packages/apps/Settings/res/values/config.xml

                     <bool name="config_show_expandedDesktop">true</bool>

        Patch set 4: Correct mistake in commit message.

        Patch set 5: Add history to commit message.

        Patch set 6: Fix whitespace error.

Change-Id: Ie35719f7503902f11f684e353e4f021150552024