Notes on understanding Android.
1 Storage
Android storage is really mind-boggling.
Background reading: https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt
2 Security
https://android.stackexchange.com/questions/210139/what-is-the-u-everybody-uid/210159#210159
Selinux?
https://android.stackexchange.com/questions/210139/what-is-the-u-everybody-uid/
Runtime permissions
https://source.android.com/devices/storage#runtime_permissions
Namespaces
https://developer.android.com/training/data-storage#scoped-storage