Convert `gsutil` usage to `gcloud storage`. NFC

`gsutil` is being phased out. Update out script to use `gcloud storage`
instead.

scripts/update_node.py

diff --git a/scripts/update_node.py b/scripts/update_node.py
index d066cde..0841e2c 100755
--- a/scripts/update_node.py
+++ b/scripts/update_node.py
@@ -46,7 +46,7 @@
     if args.upload:
       upload_url = upload_base + filename
       print('Uploading: ' + upload_url)
-      cmd = ['gsutil', 'cp', '-n', filename, upload_url]
+      cmd = ['gcloud', 'storage', 'cp', '-n', filename, upload_url]
       print(' '.join(cmd))
       subprocess.check_call(cmd)
       os.remove(filename)

scripts/update_python.py

diff --git a/scripts/update_python.py b/scripts/update_python.py
index 7aa6cfe..6a46538 100755
--- a/scripts/update_python.py
+++ b/scripts/update_python.py
@@ -86,7 +86,7 @@
     if '--upload' in sys.argv:
       upload_url = upload_base + out_filename
       print('Uploading: ' + upload_url)
-      cmd = ['gsutil', 'cp', '-n', out_filename, upload_url]
+      cmd = ['gcloud', 'storage', 'cp', '-n', out_filename, upload_url]
       print(' '.join(cmd))
       check_call(cmd)
 
@@ -169,7 +169,7 @@
     print('Created: %s' % tarball)
     if '--upload' in sys.argv:
       print('Uploading: ' + upload_base + tarball)
-      check_call(['gsutil', 'cp', '-n', tarball, upload_base + tarball])
+      check_call(['gcloud', 'storage', 'cp', '-n', tarball, upload_base + tarball])
 
 
 def main():