Disable reset report uploader

[pilgrim-brave]

Settings → Advanced → "Restore settings to their original defaults" brings up a pseudo-dialog that says "This will reset your startup page, new tab page, search engine, and pinned tabs. It will also disable all extensions and clear temporary data like cookies. Your bookmarks, history and saved passwords will not be cleared. Learn more"

The "learn more" link points to a Brave support page (good), but under the text is a checkbox (selected by default) "Help make Brave better by reporting the current settings". If checked, selecting the "Reset settings" button will send a report to a Google-owned server.

Relevant code: https://cs.chromium.org/chromium/src/chrome/browser/profile_resetter/reset_report_uploader.cc

According to @bbondy, we should

• keep the "reset settings" functionality, but
• unconditionally disable uploading of current settings
• hide the UI (checkbox) that offers the choice of uploading

Verification of upload disabling is covered by automated browser tests.

Test plan for verification of UI changes:

1. Navigate to brave://settings
2. Click 'Advanced'
3. Under 'Reset settings', click 'Restore settings to their original defaults'
4. Verify that pseudo-dialog appears, titled 'Reset settings' with some explanatory text and two buttons 'Cancel' and 'Reset settings'
5. Verify that there is NOT a checkbox that says "Help make Brave better by reporting the current settings"

[srirambv]

@pilgrim-brave can you add QA/Yes/QA/No label and any test steps in the issue/PR accordingly?

[pilgrim-brave]

Updated with test plan

[srirambv]

Verification passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta(64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Linux

Verification is passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows

Verified passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta(64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Mac OS X

• Verified steps from test plan