fix(auth): Broken l10n test (#12101)

Because:
- Underlying language strings changed and just so happened to impact test.

This Commit:
- Uses new/updated string l10n string in test.

packages/fxa-auth-server/test/local/l10n/index.ts

@@ -61,11 +61,11 @@ describe('Localizer', () => {
         );
 
         const result = await l10n.formatValue(
-          'subscriptionAccountReminderFirst-action',
+          'subscriptionAccountFinishSetup-action-2',
           {}
         );
 
-        assert.equal(result, 'Passwort erstellen');
+        assert.equal(result, 'Einführung');
       });
 
       it('localizes properly with preferred Dialect', async () => {