They want iPhone users to use their services too.
You think calling it Google instead of Android is more enticing to iPhones users?
Android to me, is a much better tech name. Google is synonymous with searching, it's verb nowadays. All of Google's services sounds like a sentence of telling someone instructions. It's no wonder all of Google services aren't the leading services in their respective categories with the exception of YouTube which doesn't bare the name Google.
And then you randomly add "Play" in the midst of everything.