Make the wait longer to ensure that async call has completed

This also aligns the interval with rest of the test code

feature_flag_test.go

@@ -752,7 +752,7 @@ func Test_DisableNotificationOnInit(t *testing.T) {
  assert.NoError(t, err)
  defer gffClient.Close()
 
- time.Sleep(1 * time.Second) // wait for the goroutine to call Notify()
+ time.Sleep(2 * time.Second) // wait for the goroutine to call Notify()
  assert.Equal(t, tt.expectedNotifyCalled, mockNotifier.notifyCalled)
  })
  }