time macos prepare script

tools/internal_ci/helper_scripts/prepare_build_macos_rc

@@ -57,25 +57,25 @@ source $HOME/.rvm/scripts/rvm
 set -e  # rvm commands are very verbose
 time rvm install 2.5.0
 rvm use 2.5.0 --default
-gem install bundler --no-ri --no-doc
-gem install cocoapods --version 1.3.1 --no-ri --no-doc
-gem install rake-compiler --no-ri --no-doc
+time gem install bundler --no-ri --no-doc
+time gem install cocoapods --version 1.3.1 --no-ri --no-doc
+time gem install rake-compiler --no-ri --no-doc
 rvm osx-ssl-certs status all
 rvm osx-ssl-certs update all
 set -ex
 
 # cocoapods
 export LANG=en_US.UTF-8
-pod repo update  # needed by python
+time pod repo update  # needed by python
 
 # python
-pip install virtualenv --user python
-pip install -U Mako six tox setuptools twisted pyyaml --user python
+time pip install virtualenv --user python
+time pip install -U Mako six tox setuptools twisted pyyaml --user python
 export PYTHONPATH=/Library/Python/3.4/site-packages
 
 # Install Python 3.7
-curl -O https://www.python.org/ftp/python/3.7.0/python-3.7.0-macosx10.9.pkg
-sudo installer -pkg ./python-3.7.0-macosx10.9.pkg -target /
+time curl -O https://www.python.org/ftp/python/3.7.0/python-3.7.0-macosx10.9.pkg
+time sudo installer -pkg ./python-3.7.0-macosx10.9.pkg -target /
 
 # set xcode version for Obj-C tests
 sudo xcode-select -switch /Applications/Xcode_9.2.app/Contents/Developer/
@@ -88,7 +88,7 @@ export DOTNET_CLI_TELEMETRY_OPTOUT=true
 # TODO(jtattermusch): better debugging of clock skew, remove once not needed
 date
 
-git submodule update --init
+time git submodule update --init
 
 # Store intermediate build files of ObjC tests into /tmpfs
 mkdir /tmpfs/Build-ios-binary-size