Despite the Android ecosystem accepts other frameworks and embrace that(the Android market doesn't forbide the use of other API's), i suggest you use the native SDK/NDK for Android, not just because they're the original tools, but for the power to develop easily anything you need. For example: using RhoStudio allows you build iOS, Android, WP7 and BlackBerry apps using the same source code, however, you are so tightly constrained to use the UI the framework generates.
In the case of Adobe Air, i think you're adding an extra layer of complexity and moreover, their performance is something we should really consider to bring a better experience.
If you are proficient using Java, you should give a try. There are a strong Android community of developers looking to help.