[PM-10686] Change the background colour of the app launcher to Bitwarden's blue

[vvolkgang]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-10686

📔 Objective

Change the app launcher background colour to Bitwarden blue when devices are using the Dark theme. Can be tested with builds from run/10282330788.

📸 Screenshots

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation or informed the documentation team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed
  issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

Checkmarx One – Scan Summary & Details – cff631b4-3d6e-4cac-919b-034884caad61

No New Or Fixed Issues Found

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.82%. Comparing base (59ba585) to head (e867ebb).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3693   +/-   ##
=======================================
  Coverage   87.82%   87.82%           
=======================================
  Files         368      368           
  Lines       30546    30546           
  Branches     4576     4576           
=======================================
  Hits        26828    26828           
  Misses       2121     2121           
  Partials     1597     1597           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.