[Telemetry] Move maps GPU test recording to public.

Maps folks have confirmed that it is public data, the same you'd get by
visiting the site.

BUG=

Review URL: https://codereview.chromium.org/526833003

Cr-Commit-Position: refs/heads/master@{#292954}

content/test/gpu/gpu_tests/maps.py

@@ -98,6 +98,7 @@ class Maps(cloud_storage_test_base.TestBase):
         util.GetChromiumSrcDir(), 'content', 'test', 'gpu', 'page_sets')
     ps = page_set.PageSet(archive_data_file='data/maps.json',
                           make_javascript_deterministic=False,
-                          file_path=page_set_path)
+                          file_path=page_set_path,
+                          bucket=page_set.PUBLIC_BUCKET)
     ps.AddPage(MapsPage(ps, ps.base_dir))
     return ps