Disable paint-holding input-suppression in 2 InputOnVizTest's

To mitigate a bug with user interactions with a stale page, we are
planning to hold back input events from a page while paint-holding is
active. Paint-holding is the browser feature to continue to show a
snapshot of the pre-navigation page (instead of a blank page) until the
renderer for the post-navigation page has pushed content to the GPU.

We have been fixing tests that would be affected by the input
suppression, and the common solution we applied is to simulate the end
of paint-holding after a page-load. All other 100+ tests have been
resolved, and the two tests here turned to be challenging. Because
InputOnViz is not a shipped yet, we are disabling input-suppression for
these tests to be able to start a finch trial for that feature.

Bug: 40057499
Change-Id: I9757cb1ed443ee92a7240438d4efa36cd8d7609c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6533981
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Reviewed-by: Vladimir Levin <vmpstr@chromium.org>
Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1460778}