This is a question that was already proposed in the past, but since there aren't any recent answers, I would like to ask it for newer models and environments.
Is it possible to install Android (e.g., a cyanogen) on a Raspberry Pi 2 (model B)? How?
I saw that there are some solutions on the web, but it is not clear to me whether they support the WiFi dongle. I do not have the possibility of using the Ethernet cable...
There has been no change with the Pi2. There is not a usable version of Android for the Raspberry Pi.
In my opinion there is unlikely to ever be a usable version based on the Broadcom 2380/2390 SOC.
For a perhaps contrary view visit https://groups.google.com/forum/#!forum/android-rpi which is dedicated to Android on the Raspberry Pi.
There are versions available for download, some of which require Linux to flash. However there are no fully stable versions available.
For a quick and easy Android 4.4 Kitkat installation, you can install BerryBoot on your Pi and download Android using its GUI.
Here's the link to a video tutorial on how to install Kitkat with BerryBoot.
Berryboot does support WiFi, but the actual Android doesn't. However you can use an Ethernet cable to connect to PC and share its WiFi connection with your Raspberry Pi.
