Make gradle update script runnable on macos (#374074)

      MITM_CACHE_PID="$!"

      # wait for mitm-cache to fully start

      for i in {0..20}; do

        ps -p "$MITM_CACHE_PID" >/dev/null || (echo "Failed to start mitm-cache" && exit 1)

        kill -0 "$MITM_CACHE_PID" 2>/dev/null || (echo "Failed to start mitm-cache" && exit 1)

        curl -so/dev/null "$MITM_CACHE_ADDRESS" && break

        [[ "$i" -eq 20 ]] && (echo "Failed to start mitm-cache" && exit 1)

        sleep 0.5