fix(android): drawer events for rightView

[m1ga]

Currently the drawer events are not connected when you don't use a leftView.

Test:

const drawerWindow = Ti.UI.createWindow();
const centerView = Ti.UI.createView();
const menuView = Ti.UI.createView({backgroundColor:"red"});
const btn = Ti.UI.createButton({title:"open"});
centerView.add(btn);
btn.addEventListener("click", function(e){ drawer.toggleRight() });

const drawer = Ti.UI.Android.createDrawerLayout({
	centerView: centerView,
	rightView: menuView,
});

drawerWindow.add(drawer);
drawerWindow.open();

drawer.addEventListener("close", function(e) {
	Ti.API.info("drawer close");
});
drawer.addEventListener("open", function(e) {
	Ti.API.info("drawer open");
});
drawer.addEventListener("slide", function(e) {
	Ti.API.info("drawer slide");
});
drawer.addEventListener("change", function(e) {
	Ti.API.info("drawer change");
});

Ti 11.1.1: no events are shown in the logs
with this PR: events are shown.

[dieskim]

Thanks for adding this fix