Even if relatively small in market size compared to current Android install base I think Google would like to grab some of Apple's profit from the high end. While Apple has around 17% of unit sales in smartphones they earn something like 91% of the profit [1]. I'm sure other competitors will be aiming to get some of that profit for themselves or at least make life hard for Apple by using competition to drive down Apple's margins.

[1] http://www.forbes.com/sites/chuckjones/2016/02/13/apples-iph...