Within the EU, it's almost certainly an abuse of their monopoly position, which is (one of the reasons) why they're being investigated.

"The Commission will assess if, by entering into anticompetitive agreements and/or by abusing a possible dominant position, Google has illegally hindered the development and market access of rival mobile operating systems, mobile communication applications and services in the European Economic Area (EEA)."

US regulators are unlikely to bat an eye. They didn't have a problem with Microsoft bundling IE and Windows Media Player with Windows, they won't have a problem with this.