Fix #8087: VPN Reset Configuration Clear confirmation

[soner-yuksel]

Summary of Changes

This pull request fixes #8087

An alert is added for confirmation success case
Additionally color fix for profile add screen

Submitter Checklist:

• Unit Tests are updated to cover new or changed functionality
• User-facing strings use NSLocalizableString()
• New or updated UI has been tested across:
  • Light & dark mode
  • Different size classes (iPhone, landscape, iPad)
  • Different dynamic type sizes

Test Plan:

• Launch Brave
• Three-dot menu > VPN
• Buy a subscription and Install VPN profile
• Three-dot menu > Settings > Brave Firewall + VPN
• Reset Configuration > Reset > Observe

Screenshots:

Reviewer Checklist:

• Issues include necessary QA labels:
  • QA/(Yes|No)
  • bug / enhancement
• Necessary security reviews have taken place.
• Adequate unit test coverage exists to prevent regressions.
• Adequate test plan exists for QA to validate (if applicable).
• Issue and pull request is assigned to a milestone (should happen at merge time).