message: build-android-arm64.sh android NDK23 updates
  - toolchain path and tool paths updated to single prebuilt toolchain folder
  - new run_native_jar routine invokes gradle build only for arm64 native jar, faster builds
  - uses compilers with api 24
diff: @@ -10,16 +10,18 @@ export os_arch=arm64
  export os_build=android
  export android_api=24
  export SHARED_LIB=lib${LIBRARY_NAME}.so
  -export ANDROID_TOOLCHAIN=/src/android-toolchain-arm64
  -export PATH=${ANDROID_TOOLCHAIN}/aarch64-linux-android/bin:${PATH}
  -export CXX=${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android-clang++
  -export CC=${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android-clang
  +export NDK_VERSION=r23
  +export ANDROID_TOOLCHAIN=/src/android-ndk/toolchains/llvm/prebuilt/linux-x86_64
  +export PATH=${ANDROID_TOOLCHAIN}/bin:${PATH}
  +export CXX=${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android${android_api}-clang++
  +export CC=${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android${android_api}-clang
  android_env
  common_env
  check_min_req_vars
  -export run_readelf="${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android-readelf -d bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}"
  -export run_bjam="${BOOST_ROOT}/b2 -j8 --user-config=config/${os_build}-${os_arch}-config.jam variant=release toolset=clang-${os_arch} target-os=${os_build} location=bin/release/${os_build}/${os_arch}-v8a"
  -export run_strip="${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android-strip --strip-unneeded -x -g bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}"
  -export run_objcopy="${ANDROID_TOOLCHAIN}/bin/aarch64-linux-android-objcopy --only-keep-debug bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB} bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}.debug"
  +export run_bjam="${BOOST_ROOT}/b2 -j8 -q --debug-building --user-config=config/${os_build}-${os_arch}-config.jam variant=release toolset=clang-${os_arch} target-os=${os_build} location=bin/release/${os_build}/${os_arch}-v8a"
  +export run_objcopy="${ANDROID_TOOLCHAIN}/bin/llvm-objcopy --only-keep-debug bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB} bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}.debug"
  +export run_strip="${ANDROID_TOOLCHAIN}/bin/llvm-strip --strip-unneeded -x -g bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}"
  +export run_readelf="${ANDROID_TOOLCHAIN}/bin/llvm-readelf -d bin/release/${os_build}/${os_arch}-v8a/${SHARED_LIB}"
  +export run_native_jar="./gradlew nativeAndroidArm64Jar"
  export BOOST_ROOT=/src/boost_${BOOST_UNDERSCORE_VERSION} && ./run-swig.sh
  build_libraries
  