fix(cksum): exclude Android from --debug flag tests

The --debug flag tests call CpuFeatures::detect() which executes the x86 CPUID
instruction. On the Android x86_64 emulator, this crashes the adb process with
exit code 137 (SIGKILL).

This fix excludes the debug flag tests from Android builds by adding
#[cfg(not(target_os = "android"))] attributes to:
- test_debug_flag()
- test_debug_with_algorithms()

These tests are not needed on Android since the --debug flag functionality
is not critical for the Android build, and the CPUID instruction is not
available on the emulator.

Fixes: Android CI job failure with exit code 137
Resolves: PR uutils#9088 Android x86_64 emulator crash during tests

Author: naoNao89

tests/by-util/test_cksum.rs

@@ -2747,6 +2747,7 @@ mod format_mix {
 }
 
 #[test]
+#[cfg(not(target_os = "android"))]
 fn test_debug_flag() {
     // Test with default CRC algorithm - should output CPU feature detection
     new_ucmd!()
@@ -2792,6 +2793,7 @@ fn test_debug_flag() {
 }
 
 #[test]
+#[cfg(not(target_os = "android"))]
 fn test_debug_with_algorithms() {
     // Test with SHA256 - CPU detection should be same regardless of algorithm
     new_ucmd!()