Revised copy for help improve UI on the new onboarding page

[nullhook]

Resolves brave/brave-browser#27339

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run lint, npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[rebron]

++ Looks good.

[DJAndries]

lgtm

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[kjozwiak]

Verification PASSED on Win 11 x64 using the following build(s):

Brave | 1.48.58 Chromium: 108.0.5359.128 (Official Build) nightly (64-bit)
-- | --
Revision | 1cd27afdb8e5d057070c0961e04c490d2aca1aa0-refs/branch-heads/5359@{#1185}
OS | Windows 11 Version 22H2 (Build 22621.963)

Went through the STR/Cases outlined via brave/brave-browser#27339 (comment) and ensured the following:

• Learn more button under Send diagnostic reports if you experience a crash or freeze. opens https://support.brave.com/hc/en-us/articles/360017905872-How-do-I-enable-or-disable-automatic-crash-reporting without any issues in a NTP
• Learn more button under Share completely private and anonymous product insights about what features are being used by Brave's users. opens https://support.brave.com/hc/en-us/articles/9140465918093-What-is-P3A-in-Brave- without any issues in a NTP

Ensure that Help make Brave better. screen matches the screenshot mentioned via brave/brave-browser#27339 (comment) and the design outlined via https://www.figma.com/file/MFHpcXJMg2RUQpUJMAZZ4R/Desktop-Onboarding?node-id=4205%3A105911&t=OgwXlQ3MZKgS9Dqj-0.

[kjozwiak]

Created brave/brave-browser#27401 while running through the above. Doesn't block uplift but will need to be resolved for 1.47.x.