This got rolled out because we rely on AS to generate the clientDataJSON, so the tests that check it's value started failing. Need to either disable the tests or generate it within WACP whenever we are in a test.
<rdar://problem/122313244>
Pull request: https://github.com/WebKit/WebKit/pull/23864
Committed 274120@main (7516fcdbbaf5): <https://commits.webkit.org/274120@main> Reviewed commits have been landed. Closing PR #23864 and removing active labels.