The test_harnesses::run_harness test panics on machines without
Android NDK/SDK installed and on non-macOS platforms for iOS
assertions. Skip these assertions gracefully instead of failing
the entire test suite.
- Android assertions: skip when get_android_tools() returns None
- iOS assertions: skip when not running on macOS
Normalize line endings to LF across all platforms. Without this,
Windows contributors get CRLF warnings on every checkout and test
run due to generated harness files.