Revert "Update gce starting guide to use get.k8s.io"

cluster/gce/util.sh

@@ -28,23 +28,12 @@ NODE_INSTANCE_PREFIX="${INSTANCE_PREFIX}-minion"
 function verify-prereqs {
   local cmd
   for cmd in gcloud gsutil; do
-    if ! which "${cmd}" >/dev/null; then
-      echo "Can't find ${cmd} in PATH.  Do you wish to install the Google Cloud SDK? [Y/n]"
-      local resp
-      read resp
-      if [[ "${resp}" != "n" && "${resp}" != "N" ]]; then
-        curl https://sdk.cloud.google.com | bash
-      fi
-      if ! which "${cmd}" >/dev/null; then
-        echo "Can't find ${cmd} in PATH, please fix and retry. The Google Cloud "
-        echo "SDK can be downloaded from https://cloud.google.com/sdk/."
-        exit 1
-      fi
-    fi 
+    which "${cmd}" >/dev/null || {
+      echo "Can't find ${cmd} in PATH, please fix and retry. The Google Cloud "
+      echo "SDK can be downloaded from https://cloud.google.com/sdk/."
+      exit 1
+    }
   done
-  # update and install components as needed
-  gcloud components update preview
-  gcloud components update
 }
 
 # Create a temp dir that'll be deleted at the end of this bash session.