repo: update launcher

Change-Id: Icd88856b06e6046b8f7d1cc85a3b33f6f8f21661
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3192250
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jack Neus <jackneus@google.com>
Commit-Queue: Jack Neus <jackneus@google.com>

repo_launcher

@@ -149,7 +149,7 @@ if not REPO_REV:
 BUG_URL = 'https://bugs.chromium.org/p/gerrit/issues/entry?template=Repo+tool+issue'
 
 # increment this whenever we make important changes to this script
-VERSION = (2, 15)
+VERSION = (2, 17)
 
 # increment this if the MAINTAINER_KEYS block is modified
 KEYRING_VERSION = (2, 3)
@@ -312,6 +312,10 @@ def InitParser(parser, gitc_init=False):
                    metavar='PLATFORM')
   group.add_option('--submodules', action='store_true',
                    help='sync any submodules associated with the manifest repo')
+  group.add_option('--standalone-manifest', action='store_true',
+                   help='download the manifest as a static file '
+                        'rather then create a git checkout of '
+                        'the manifest repo')
 
   # Options that only affect manifest project, and not any of the projects
   # specified in the manifest itself.