[test] Style fixes for "Modify test scripts for aarch64 and modern NDKs"
Some style fixes that @compnerd proposed in PR #19503.
- Instead of checking for the two known ARMv7 subarchitectures, check for everything that starts with armv7 and consider it armv7.
- Try finding the current platform to select the right prebuilt directory for the NDK tools.
- Use -isystem for the system header includes when passing them to
clang.
- Modify the format strings which started to be very wild into simpler `' '.join([...])` which, IMO, read better.
- Hoist some common path parts to not repeat the same long paths in a
couple of places.
- Add more library search paths (missing for atomic)
Author
Daniel Rodríguez Troitiño