I’ve got no idea why this process is so poorly documented, nor why many of the existing resources describing how to install the AIR runtime on the Android emulator are so needlessly circuitous, pointing you to links on the official Adobe site that have moved or no longer exist.
But suffice to say, if you want to install the Adobe AIR runtime on an emulated Android device for testing or development purposes without having to wade through a ton of fuss and nonsense, you have two basic options. The first is described briefly here, and basically involves installing the latest Flash/Flex/AIR SDK from the official website and then grabbing the AIR runtime package from ‘<AIR_SDK_ROOT>/runtimes/air/android/emulator/Runtime.apk‘. This file is the AIR runtime that must be installed on the emulator for any apps built with Adobe AIR to function. And this method works fine if you don’t mind downloading and installing the entire AIR SDK (90 MB) just to grab this one file.
You other option is to use this direct link to download just the AIR runtime package (6.1 MB). Note that this is version 2.7 of the AIR runtime, and has been tested with an emulator running Android 3.1 only. I cannot vouch for it working with any other configurations.
In either case, once you have gotten a hold of the the runtime .apk file, installing it on your emulator is a relatively simple process. All you need is the ‘adb‘ utility that is included in the “Android SDK Platform Tools” package (note that this package is not the same as the similarly named “Android SDK Tools” package). If you don’t have this package installed yet, then use your Android configuration manager to install it. Then simply navigate to ‘<ANDROID_SDK_ROOT>/platform-tools‘ and run the following command (while your Android emulator is running):
adb install /path/to/your/AIR/runtime.apk
This will install the AIR runtime on your emulated device, and you can now install and run AIR-based Android apps on your emulator. Quite simple, really. Which only doubles my confusion with respect to why this simple process seems to be so poorly documented online.