Google loves open source likely for another reason than you do.
Google loves open source when they can capitalize on it.
That is, when a big community works on code that Google can use for free to build their monopolistic infrastructure. They love a global community which works for them for free. They might even foster this community as far as it serves their purpose or for image reasons.
However, if they'd truly love open-source, they could open the source code to their core services. But they'd never ever do that. For this reason they also ban the AGPL license internally (https://opensource.google/documentation/reference/using/agpl-policy). The AGPL license would force Google to open their code which relies on AGPL licensed projects. Google hates that.
Google does clearly not stand for the ethical values people usually have in mind when talking about open source. For example when something is competing with them, they'll hate it. Like ad-blockers or browsers which don't block ad-blockers like Google chrome does. The core business of Google is about surveillance and advertising. To maximize the profitability of this, then need to violate freedoms of their users (like the freedom to use their service while blocking ads). This is in direct conflict with the ethical values often implied by free and open-source software.
So if somebody tells you "Google loves open-source and contributes a lot", think about what it really means.
Or better named after oil companies.