Update experimental testing config for new LazyLoad params.

This CL updates the fieldtrial testing config to reflect new LazyLoad
parameters that have been added. These parameters reflect what will be
launched.

Bug: 937980
Change-Id: If5a9ebd4350d0f40989f890f939e4c1a4f826ddd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1635362
Auto-Submit: Scott Little <sclittle@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Scott Little <sclittle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664490}

testing/variations/fieldtrial_testing_config.json

@@ -2763,6 +2763,8 @@
                 {
                     "name": "Enabled",
                     "params": {
+                        "automatic-lazy-load-frames-enabled": "true",
+                        "automatic-lazy-load-images-enabled": "true",
                         "restrict-lazy-load-frames-to-data-saver-only": "true",
                         "restrict-lazy-load-images-to-data-saver-only": "true"
                     },