It's about dominant position. Having the sort of stifling monopoly that Google has opens it up to additional regulation, just like Microsoft was before it. Apple is a niche market still, to this day, and isn't under as much scrutiny.
You're looking at the wrong monopoly!
'apple has a monopoly on the iphone'
'GM has a monopoly on cadillac'
'BMW has a monopoly on the 3-series'
Of course they have a 'monopoly' on android, android is their product. Android has captured 64%[0] of the smartphone market in russia, this is again not a monopoly. A monopoly would capture 100% of the market, thats the definition of a monopoly.
I'm eager to hear what market Google has captured 100% of, because its not search or smartphones
[0]http://www.statista.com/statistics/262174/market-share-held-...