[M144][iOS] Update Ask Gemini Chip Text and Prefilled Prompt for Floaty

The Ask Gemini Omnibox Chip text and the prompt that shows when a
user opens the floaty with the flag kAskGeminiChipPrepopulateFloaty
enabled is being changed.

UI Video: crbug.com/466413500#attachment71556098

(cherry picked from commit 1eda5296da3340710f746695ae05316513f63b82)

Fixed: 466413500
Fixed: 466419647
Change-Id: I080427a4cd10cd3e58eae7145273aba94ad0561f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7232431
Reviewed-by: Adam Arcaro <adamta@google.com>
Auto-Submit: Joemer Ramos <joemerramos@google.com>
Commit-Queue: Joemer Ramos <joemerramos@google.com>
Cr-Original-Commit-Position: refs/heads/main@{#1555182}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7242012
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Daniel Yip <danielyip@google.com>
Commit-Queue: Krishna Govind <govind@chromium.org>
Reviewed-by: Krishna Govind <govind@chromium.org>
Owners-Override: Daniel Yip <danielyip@google.com>
Cr-Commit-Position: refs/branch-heads/7559@{#628}
Cr-Branched-From: 223dfbac1c7542a06b422390d954afe5b560b607-refs/heads/main@{#1552494}