Remove duplicate 'start' call for the account manager

We are already starting the account manager in BackgroundServices,
so this call is a no-op (its gets dropped by the state machine).

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

@@ -324,8 +324,6 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
 
         components.backgroundServices.accountManagerAvailableQueue.runIfReadyOrQueue {
             lifecycleScope.launch {
-                // Make sure accountManager is initialized.
-                components.backgroundServices.accountManager.start()
                 // If we're authenticated, kick-off a sync and a device state refresh.
                 components.backgroundServices.accountManager.authenticatedAccount()?.let {
                     components.backgroundServices.accountManager.syncNow(