fix(android): TabGroup crashes if tab "title" property not set as of 8.0.2

[jquick-axway]

JIRA:
https://jira.appcelerator.org/browse/TIMOB-27188

Summary:

• TIMOB-27188 Fixed bug where TabGroup will crash if "title" property is null or left undefined.
  • This is a regression as of Titanium 8.0.2.
• Added additional null checks to TabGroup Java code.
• Added icon-only tab group unit tests for top/bottom styles.

Test:

1. Create a Classic "Default Project".
2. Replace project's "app.js" with the below code.
3. Build and run on Android.
4. Verify 2 tabs appear at the top without titles; only icons. (This used to crash.)
5. Tap on the right tab.
6. In the log, verify the following was printed: Tab 1 was unselected
7. In the log, verify the following was printed: Tab 2 was selected
8. In the code below, uncomment the tabGroupSettings.style line.
9. Rebuild and run on Android.
10. Verify 2 tabs appears at the bottom without titles; only icons. (This used to crash.)
11. Tap on the right tab.
12. In the log, verify the following was printed: Tab 1 was unselected
13. In the log, verify the following was printed: Tab 2 was selected
14. In the code below, uncomment the title: title line.
15. Rebuild and run on Android.
16. Verify that the bottom tabs have both titles and icons.
17. In the code below, comment-out (or delete) the tabGroupSettings.style line.
18. Rebuild and run on Android.
19. Verify that the top tabs have both titles and icons.

function createTab(title, iconPath) {
	var window = Ti.UI.createWindow({ title: title });
	window.add(Ti.UI.createLabel({ text: title + " View" }));
	var tab = Ti.UI.createTab({
//		title: title,
		icon: iconPath,
		window: window,
	});
	tab.addEventListener("unselected", function(e) {
		Ti.API.info("@@@ " + title + " was unselected.");
	});
	tab.addEventListener("selected", function(e) {
		Ti.API.info("@@@ " + title + " was selected.");
	});
	return tab;
}

var tabGroupSettings = {
	tabs: [
		createTab("Tab 1", "/assets/images/tab1.png"),
		createTab("Tab 2", "/assets/images/tab2.png")
	],
};
if (Ti.Android) {
//	tabGroupSettings.style = Ti.UI.Android.TABS_STYLE_BOTTOM_NAVIGATION;
}
var tabGroup = Ti.UI.createTabGroup(tabGroupSettings);
tabGroup.open();

[build]

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	✅ All tests are passing Nice one! All 29 tests are passing. (There are 6 tests skipped)

Generated by 🚫 dangerJS against af619d0

[ypbnv]

LGTM!

And thank you for taking care of this!

[keerthi1032]

FR passed. No tab group crash if title property set/not .tested with the test case provided in the PR.
Test Environment:
Name = Mac OS X
Version = 10.14.5
Architecture = 64bit
Node.js
Node.js Version = 8.9.1
npm Version = 5.5.1
Titanium CLI
CLI Version = 5.1.1
Titanium SDK
SDK Version = 8.2.0.v20190626210412
Device = oneplus 5t android 9,nexus 5 ANDORID 5,
Emulator = pixel 3xl android 9