Make "All rights reserved" Optional in the License

This update is per http://crrev.com/1031130 where OSS licensing
requested removal of "All rights reserved" from new files.

Change-Id: I52a9deab99539ea90403798606c7bbeb261df994
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3811744
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Auto-Submit: Robert Liao <robliao@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>

presubmit_canned_checks.py

@@ -652,9 +652,11 @@ def CheckLicense(input_api, output_api, license_re=None, project_name=None,
     key_line = ('Use of this source code is governed by a BSD-style license '
                'that can be')
     # The (c) is deprecated, but tolerate it until it's removed from all files.
+    # "All rights reserved" is also deprecated, but tolerate it until it's
+    # removed from all files.
     license_re = (
-        r'.*? Copyright (\(c\) )?%(year)s The %(project)s Authors\. '
-          r'All rights reserved\.\r?\n'
+        r'.*? Copyright (\(c\) )?%(year)s The %(project)s Authors\.'
+          r'( All rights reserved\.)?\r?\n'
         r'.*? %(key_line)s\r?\n'
         r'.*? found in the LICENSE file\.(?: \*/)?\r?\n'
     ) % {