If you read the docs page in the link you posted in your comment on your question it says...
Note: Later in this class, you will learn how to make your app compatible down to Android 2.1 (API level 7) for devices that do not support SearchView.
You need to look at Remaining Backward Compatible which uses the v7 compatibility library to supporrt back to API 7 (Eclair). BTW, API 8 is Froyo (Android v2.2).