I have created a comprehensive list of such OSes at https://softwarerecs.stackexchange.com/a/90902/73901.

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##### AOSP

The hierarchy of the AOSP filesystem is similar to what you have described, because each package is isolated within `/data`.



https://developer.android.com/training/data-storage demonstrates this. However, should you want to confirm:

1. * Outside the OS:

 ```sh
 adb
 ```

 * Alternatively, from within AOSP:

 ```sh
 shell
 ```
1. ```sh
 tree
 ```

provides evidence that superuser access is available.