A lot of words to bring attention to android.os.Build. While you were in there, did you notice any other interesting fields? Any usable info in BOARD, DEVICE, FINGERPRINT, HARDWARE, MANUFACTURER, MODEL, PRODUCT?
I can't think of a situation where the distinction between hardware and emulator is needed. Yes, I may need to know if the device has WIFI or bluetooth or other characteristics not available on an emulator, but all of these can be determined by other means.