cros-suggest: roll text suggester experiments mojom

This CL rolls the recent text suggester experiment mojom updates to
chromium.

Note there are changes in a number of other mojom files, these are a
simple shared comment update that felt harmless to include in this CL
as these changes needed to be uprev'd at some point.

Bug: chromium:3045828
Change-Id: I7aa6010b21e878d41c722b04e81794fd48566781
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3045466
Commit-Queue: Darren Shen <shend@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Andrew Moylan <amoylan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#911156}