Frozen mobile fix

[jeremiah-huston]

What this changes, and why

Fix for app freezing on mobile resume

Closes #

What you tested

Checks

• dotnet build Serval.slnx — no warnings, not just no errors
• dotnet test Serval.slnx
• dart format . in App/serval_app reports no files changed
• flutter analyze is silent, info included
• flutter test passes — and if the design changed, flutter test --update-goldens and the
  new captures are committed in this branch
• pubspec.lock is committed alongside any pubspec.yaml edit (CI resolves with
  --enforce-lockfile)
• I have signed the CLA, or will when
  the bot asks