gradle: fix usage of update-deps script without bwrap (#418576)

      export MITM_CACHE_CERT_DIR="$PWD"

      export MITM_CACHE_CA="$MITM_CACHE_CERT_DIR/ca.cer"

      popd >/dev/null

      useBwrap="''${USE_BWRAP:-${toString useBwrap}}"

      if [ -n "$useBwrap" ]; then

      useBwrap="''${USE_BWRAP:-${if useBwrap then "1" else "0"}}"

      if [[ "$useBwrap" -ne 0 ]]; then

        # bwrap isn't necessary, it's only used to prevent messy build scripts from touching ~

        bwrap \

          --unshare-all --share-net --clearenv --chdir / --setenv HOME /homeless-shelter \