[TIMOB-27271] Android: Resuming with intent using "FLAG_ACTIVITY_MULTIPLE_TASK" can hang the app

*Summary:* Resuming an app with an intent having FLAG_ACTIVITY_MULTIPLE_TASK set causes it to hang in Titanium 8.0.0 if the app does not immediately open a window via its "newintent" event. Titanium 7.x.x and older isn't much better. It won't hang on startup, but will instead create a new splash screen activity instance and do nothing. *Note:* The Android OS will automatically add the FLAG_ACTIVITY_MULTIPLE_TASK to intents assigned the ACTION_SEND action. So, apps whose intent-filter do not handle "intent-filter" ACTION_SEND typically don't have to worry about this issue. *Steps to reproduce:*

Create a classic Titanium app.

Set project name to "IntentTest". _(This is <name/> in "tiapp.xml".)_

Set project's "Application Id" to "com.appc.intent.test". _(This is <id/> in "tiapp.xml".)_

Set up the "app.js" with the below code.

Build and run on Android.

Open the Mac "Terminal".

CD (change directory) to: ~/Library/Android/sdk/platform-tools

In the terminal, enter the following...

./adb shell am start -n com.appc.intent.test/.IntenttestActivity -a android.intent.action.VIEW -d https://www.appcelerator.com -f 0x08000000

app.js

Ti.Android.rootActivity.addEventListener("newintent", function(e) {
	label.text = "New Intent:\n" + JSON.stringify(e.intent, null, 4);
	Ti.API.info("@@@ newintent: " + JSON.stringify(e.intent));
});

var window = Ti.UI.createWindow();
var scrollView = Ti.UI.createScrollView({
	scrollType: "vertical",
	width: Ti.UI.FILL,
	height: Ti.UI.FILL,
});
var label = Ti.UI.createLabel({
	text: "Launch Intent:\n" + JSON.stringify(Ti.Android.rootActivity.intent, null, 4),
	width: Ti.UI.FILL,
	height: Ti.UI.SIZE,
});
scrollView.add(label);
window.add(scrollView);
window.open();

*Result:* In Titanium 8.0.0 and higher, the app hangs. Also notice in the log that the "newintent" is being logged non-stop, meaning the "newintent" event is being fired repeatedly when it should only be fired once. In Titanium versions older than 8.0.0, a new splash screen activity window is displayed, but nothing happens. Note that the app is not hung and you can back-out of the splash window, but this is still not good behavior. *Expected Result:* The "newintent" event should only be fired once and not hang the app. *Work-around:* Immediately open a window when a "newintent" is received set with this flag. If you don't want to open a window immediately, then you can instead quickly open/close a temporary window when this flag is set. Note that closing a window immediately as shown below prevents it from ever being shown, because Titanium destroys it via the activity's onCreate() method.

Ti.Android.rootActivity.addEventListener("newintent", function(e) {
	// This works-around the issue.
	if (e.intent.flags & Ti.Android.FLAG_ACTIVITY_MULTIPLE_TASK) {
		var window = Ti.UI.createWindow();
		window.open();
		window.close();
	}
});

_(I've tested the below on Android Q while target API Level 29. It works fine.)_