Ignore public API checks if COMMIT=false is in the description

BUG=skia:
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/d1783aefcc0da86c5ff1d124c54704252d817621

Review URL: https://codereview.chromium.org/1006473002
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index d62249a..ae5a218 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -254,6 +254,11 @@
       # It is a revert CL, ignore the public api owners check.
       return results
 
+    if re.search(r'^COMMIT=false$', issue_properties['description'], re.M):
+      # Ignore public api owners check for COMMIT=false CLs since they are not
+      # going to be committed.
+      return results
+
     match = re.search(r'^TBR=(.*)$', issue_properties['description'], re.M)
     if match:
       tbr_entries = match.group(1).strip().split(',')