[TIMOB-26865] Android: Activity "onRestart" callback no longer invoked as of 8.0.0.RC

*Summary:* As of Titanium 8.0.0.RC, the Activity callback assigned to [onRestart](https://docs.appcelerator.com/platform/latest/#!/api/Titanium.Android.Activity-property-onRestart) is no longer invoked. This is a regression. The "onRestart" callback is supposed to be invoked after the activity's "onStop" to indicate that the activity window is being resumed from the background. *Steps to reproduce:*

Build and run the below code on Android.

Wait for the app to appear onscreen

Press the "Home" button to suspend the app.

Resume the app.

Observe the log and notice that "onRestart" was not logged.

var window = Ti.UI.createWindow();
window.add(Ti.UI.createLabel({ text: "Activity onRestart Test" }));
window.activity.onRestart = function() {
	Ti.API.info("@@@ Activity.onRestart() called.");
	Ti.UI.createNotification({
		message: "Activity.onRestart() called.",
		duration: Ti.UI.NOTIFICATION_DURATION_SHORT,
	}).show();
};
window.open();