message: Fix grpc_php_plugin setup
diff: add_bazel() {
  - if [ ! "$(command -v bazel)" ]; then
  - os=$(uname -s)
  - if [ "$os" = "Linux" ]; then
  + if ! command -v bazel; then
  + if [ "$(uname -s)" = "Linux" ]; then
  ${apt_install:?} curl gnupg
  get -s -n "" https://bazel.build/bazel-release.pub.gpg | sudo apt-key add -
  echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel.list
  sudo "${debconf_fix:?}" apt-get update -y
  ${apt_install:?} bazel
  - elif [ "$os" = "Darwin" ]; then
  + else
  brew install bazel
  fi
  fi
  @@ -33,8 +32,7 @@ add_grpc_php_plugin() {
  get -s -n "" "https://github.com/grpc/grpc/archive/$grpc_tag.tar.gz" | tar -xz -C /tmp
  cd "/tmp/grpc-${grpc_tag:1}" || exit
  add_bazel
  - echo "os: $os"
  - echo "release: $DISTRIB_RELEASE"
  + [ "$(uname -s)" = "Darwin" ] && sudo xcode-select -s /Applications/Xcode_11.7.app
  if [ "$DISTRIB_RELEASE" = "16.04" ]; then
  CC="$(command -v gcc)" CXX="$(command -v g++)" ./tools/bazel build src/compiler:grpc_php_plugin
  else
  