I’m not familiar with such solutions, but I wouldn’t get your hopes high, as Google Docs is not a collection of publicly available files (like YouTube), rather files closed behind different accesses.
Based on this, depending on how a file is shared with you, you could be asked to authenticate yourself somehow. Without the deeper understanding of your situation, I can only think of one solution: downloading these files with manipulating the links, like this for example (if they are public): https://stackoverflow.com/questions/9045392/getting-the-download-link-for-a-public-google-docs-file?rq=1
If they are not public, I think you still have the chance to do this, but I can’t see any steps around authenticating with Google in their own site. And then download the file.
I’m mostly on board with this, but even with using only trusted, vetted… apps (which is already a huge challenge for some) I wouldn’t go for sure that none of those are going rouge (as we saw before: some adv company buying a decent SW and making it a bloatware).
Getting back to my first point: I just had a situation where I had to install Viber for example, and I can’t stress enough how grateful I was for the Storage and Contact scopes features.
As others already stated there are solutions already to pin apps and to be honest, I feel I would not give the phone to a policeman like that.
On the other hand, what I’m more concerned about is giving the access to my phone’s data through different permissions to my government.
For example this is the list of permissions for the Hungarian government app: https://reports.exodus-privacy.eu.org/en/reports/hu.gov.dap.app/latest/#trackers