build_android_apk.sh no longer requires all four env vars to be set
manually. It probes common SDK paths and uses the newest installed
build-tools/NDK/platform when vars are absent. Also adds llvm-strip
pass to strip debug symbols from .so files before packaging (controlled
by STRIP_NATIVE_LIBS, default 1), moves the debug keystore to a stable
target/android/debug.keystore path, and prints resolved paths at start.
Also adds scripts/ANDROID_TESTING.md and scripts/android_smoke.sh for
on-device smoke testing.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
funman300