Android Integration

### Please agree to the following

- [x] I have searched [existing issues](https://github.com/cryptomator/android/issues?q=) for duplicates
- [x] I agree to follow this project's [Code of Conduct](https://github.com/cryptomator/android/blob/develop/.github/CODE_OF_CONDUCT.md)

### Summary

Android document provider features to work with other apps

### Motivation

I'm using a fairly new app with Good support with veracrypt file/drive and have full android document provider support for other apps.

It's a open source app called vault Explorer lacks cloud storage support.

https://github.com/R0b0To/VaultExplorer

### Considered Alternatives

_No response_

### Anything else?

_No response_

Start by reviewing Android document provider features and the linked VaultExplorer app to understand the interoperability goal. Define which document-provider capabilities should be supported and how support will be verified; the issue does not identify repository files, tests, or a concrete acceptance criterion.

Written by the indexing model from the issue text.