Update gsutil version to 4.30

This is the current version being used by Chromium. Without doing this,
download_from_google_storage does not work.

For more context see here:
https://groups.google.com/a/google.com/forum/#!msg/clank-dev/RdHk6odumRQ/8kkAEpPhDAAJ
https://cs.chromium.org/chromium/tools/depot_tools/gsutil.py?sq=package:chromium&dr=C&l=159

Change-Id: If2d0992cb2d080e9eb8b29d66db74235a9eafc60
diff --git a/download_from_google_storage.py b/download_from_google_storage.py
index 44cc3a7..af57aed 100755
--- a/download_from_google_storage.py
+++ b/download_from_google_storage.py
@@ -54,7 +54,7 @@
 class Gsutil(object):
   """Call gsutil with some predefined settings.  This is a convenience object,
   and is also immutable."""
-  def __init__(self, path, boto_path=None, timeout=None, version='4.7'):
+  def __init__(self, path, boto_path=None, timeout=None, version='4.30'):
     if not os.path.exists(path):
       raise FileNotFoundError('GSUtil not found in %s' % path)
     self.path = path
diff --git a/gsutil.py b/gsutil.py
index 53589a2..fffb023 100755
--- a/gsutil.py
+++ b/gsutil.py
@@ -108,7 +108,7 @@
 
 def parse_args():
   parser = argparse.ArgumentParser()
-  parser.add_argument('--force-version', default='4.13')
+  parser.add_argument('--force-version', default='4.30')
   parser.add_argument('--fallback', default=DEFAULT_FALLBACK_GSUTIL)
   parser.add_argument('--target', default=DEFAULT_BIN_DIR)
   parser.add_argument('args', nargs=argparse.REMAINDER)