Android CI keeps failing in file-related tests

Start with .github/workflows/android.yml and the failures in tests/common/util.rs, tests/by-util/test_env.rs, test_cat::test_closes_file_descriptors, and test_split::test_round_robin_limited_file_descriptors. Reproduce the Android CI failures and compare the file-handling behavior and errors across the affected tests. Done means the Android workflow passes consistently for these file-related tests.

Android CI has been failing quite consistently over the last day or so:
https://github.com/uutils/coreutils/actions/workflows/android.yml

The errors are don't always hit the same tests, but all seem to have something to do with file handling. A random selection follows:

coreutils::tests test_cat::test_closes_file_descriptors
[2025-03-23 09:44:15] 
[2025-03-23 09:44:15] thread 'test_cat::test_closes_file_descriptors' panicked at tests/common/util.rs:1794:37:
[2025-03-23 09:44:15] called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }
...
[2025-03-23 09:44:15] ──── TRY 3 STDERR:       coreutils::tests test_env::test_env_permissions
[2025-03-23 09:44:15] 
[2025-03-23 09:44:15] thread 'test_env::test_env_permissions' panicked at tests/by-util/test_env.rs:88:10:
[2025-03-23 09:44:16] assertion failed: `(left == right)`
[2025-03-23 09:44:16] 
[2025-03-23 09:44:16] Diff < left / right > :
[2025-03-23 09:44:16] <env: unknown error: Os { code: 21, kind: IsADirectory, message: "Is a directory" }
[2025-03-23 09:44:16] >env: '.': Permission denied
...
[2025-03-23 00:57:00] ──── TRY 3 STDERR:       coreutils::tests test_split::test_round_robin_limited_file_descriptors
[2025-03-23 00:57:00] 
[2025-03-23 00:57:00] thread 'test_split::test_round_robin_limited_file_descriptors' panicked at tests/common/util.rs:1794:37:
[2025-03-23 00:57:00] called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }
...
[2025-03-23 00:57:00]   TRY 3 FAIL [   0.188s] coreutils::tests test_split::test_round_robin_limited_file_descriptors
[2025-03-23 00:57:00] ──── TRY 3 STDOUT:       coreutils::tests test_split::test_round_robin_limited_file_descriptors
[2025-03-23 00:57:00] 
[2025-03-23 00:57:00] running 1 test
[2025-03-23 00:57:00] run: /data/data/com.termux/files/home/coreutils/target/debug/coreutils split -n r/40 onehundredlines.txt
[2025-03-23 00:57:00] test test_split::test_round_robin_limited_file_descriptors ... FAILED
...