Fix typo in fetch_all.py

Typo was causing script to fail with:
TypeError: __init__() got an unexpected keyword argument 'actino'

Change-Id: I9ea784032a5a5a5e4fe7659804d797db799068f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1707171
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678517}

tools/android/roll/android_deps/fetch_all.py

@@ -341,7 +341,7 @@ def main():
       help='Reset your Chromium workspace to its HEAD state, but preserves '
       'build.gradle changes. Use this to undo previous --update-all changes.')
   parser.add_argument(
-      '--debug', actino='store_true', help='Enable debug logging')
+      '--debug', action='store_true', help='Enable debug logging')
   args = parser.parse_args()
 
   # Determine Chromium source tree.