Add OmniboxTypedSuggestionGrouping to fieldtrial testing config.

Bug: b:328632631
Change-Id: I8517b2ab42f2f5b04cc11ed4c1e785976e908bde
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5354706


Auto-Submit: Tomasz Wiszkowski <ender@google.com>
Commit-Queue: Tomasz Wiszkowski <ender@google.com>
Reviewed-by: Patrick Noland <pnoland@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1269932}