So does that mean someone else could choose to announce and launch Android Nutella...?
No. Contrary what some people seem to believe, Google effectively "owns" Android. For a start, Google owns the Android trademark which means that no one else is allowed to market an "Android Nutella". Google is also the entity in charge of the Android Open Source Project (AOSP) and every modification to the project's source code has to be approved by them, which means that the development is entirely under Google's control. Google can also at any time revoke or change the licence for the AOSP, but of course not retroactively for the code already released. Crucially, the AOSP is not even the complete Android, it misses a lot of the proprietary code that Google and OEMs add themselves, such as Google Play Services, Google apps, drivers, OEM skins and so forth. The final software that people have on their phones is to a large extent proprietary.
However, anyone could fork the AOSP as long as the licence remains permissive. This is what Amazon did. They took AOSP, added their own drivers, skin and applications to it. But they are not allowed to call it Android and they don't have any control over the AOSP. Moreover, given that Google has increasingly diverted resources away from the AOSP and into its own Google products, notably Google Play Services and the Google Play Store, the development of the open-source parts is hampered, making it much less attractive for anyone else to fork the project. Without Google's approval, you don't get the Google Play Store and you don't get the Google Play Services layer that enables a lot of features in apps.
To turn to the OP's question: Google may "own" Android, but Android is incomplete. It lacks drivers for the great variety of hardware that is out there. These drivers are in turn proprietary again and owned by hardware manufactures. Moreover, Google has barely a foothold in the smartphone market. Even the Nexus devices are not Google's, they are the result of a much closer cooperating with certain OEMs. Google has effectively no control over the hardware, it's entirely dependent on licensing agreements and other contracts. This combined with the powers carriers have in some countries makes Google very vulnerable and it's position of power is fragile if push comes to shove.
You really can't compare this to Apple. Apple controls every step of the process. They make separate deals with manufacturers of the individual components, they have deals with companies who assemble the phones, they design some of the hardware and industrial processes themselves, they write the software, including drivers, they provide the App Store. Apple has reached its strength on its own and still carefully controls everything. Google has never had that ambition, presumably because they were caught off guard when Apple showed the iPhone. In fact, even Android was not a project of their own, it was a takeover. Google needed to build Android rapidly and needed all the support it could get. It's now paying the price for that.