Enabled diagnostic reporting by default

[nullhook]

Resolves brave/brave-browser#27126
Resolves brave/brave-browser#27253

Security review: https://github.com/brave/security/issues/1132

We enable diagnostic reporting by default on the new Welcome UI

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, npm run lint, 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

[fmarier]

I'm a bit confused. The PR is for changing the P3A default, but the linked issue is for changing the crash reporting default.

Which setting is this PR meant to change?

[nullhook]

Good catch, looks like the callbacks were swapped. Just to confirm, the first checkbox handles metrics reporting, and the second checkbox handles P3A.

The PR is intended to change the metrics reporting default. Both options should now be checked by default and also should call the correct callbacks.

[brave-builds]

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

[fmarier]

I was confused about this initially, but @nullhook cleared it up for me in a Slack DM:

"metrics reporting" refers to automatic crash reporting

This PR does two things:

• It corrects the naming of the checkboxes in the code (the crash report setting was controlled by the p3a variable and vice-versa) -- no user-visible changes.
• It changes the default for crash reporting to ON by default (i.e. opt out) -- covered by the linked security review.

[fmarier]

The part of the changes which corrects the naming of the variables looks great.

I'll put my review on hold because of the second part of this change (changing the crash reporting default) until the security review is complete.

[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 | 1.48.57 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)

Test Case #1 - brave/brave-browser#27126

Using the STR/Cases outlined via brave/brave-browser#27126 (comment), ensured that Send diagnostic reports if Brave crashes or freezes is set is enabled (opt-out) as per #16208 (comment). Also ensured that it appeared enabled via brave://settings/privacy.

Example	Example

Test Case #2 - brave/brave-browser#27253

Using the STR/Cases outlined via brave/brave-browser#27253 (comment), ensured that Allow privacy-preserving product analytics (P3A) is enabled via brave://settings/privacy as per the following:

Example	Example

[bridiver]

this old version was wrong because it should be true for nightly and beta, but the new version is also implemented incorrectly. If we want to default to true, we should change the default pref value, not the UI