The logo was first used on Android 1.0 and was continued to be used on Android Jelly Bean and KitKat after the new wordmark was introduced and it is currently unused as of September-October 2015 when Google introduced the new logo with the new wordmark.
The new wordmark for Android was introduced at the Google I/O event in June 26, 2014, first used in Android 4.4.4 KitKat and debuted with Android Lollipop in October-November 2014. This logo is also similar to the logos for Bloomingdale's and Macy's.
This logo is used on the Android website as well as on the "Be Together. Not The Same." ad campaign.