Fix flakey AuthenticationService test. (#4270)

The AppSettings overrides were being propagated.

UnitTests/Sources/ServerConfirmationScreenViewModelTests.swift

@@ -22,7 +22,8 @@ class ServerConfirmationScreenViewModelTests: XCTestCase {
     override func setUp() {
         AppSettings.resetAllSettings()
         appSettings = AppSettings()
-        ServiceLocator.shared.register(appSettings: appSettings)
+        // These app settings are kept local to the tests on purpose as if they are registered in the
+        // ServiceLocator, the providers override that we apply will break other tests in the suite.
     }
     
     override func tearDown() {