I kindly beg you to search more and more. Your topic is a rare and helpful one I also appreciate that but I think you just need to increase your Googling Abilities :D
I guess I know what you were searching for so I just searched about your topic and the result is exactly what you need I am sure.
You know,, you can not access android device-specific libraries and features with AS3 for these are not available in the built-in AS3 classes. There are some air extensions provided to help us the air developers who want to make Android or iOS apps though.
Am I clear enough? if not go to this link please. Here you can learn more and even use some extensions in your projects if necessary: http://www.adobe.com/devnet/air/native-extensions-for-air.html
And a happy link for you and your topic: http://www.myappsnippet.com/loading-dialog-air-extension
Just tell me if this is what you wanted. I'll be happy!