Fix loading state overlapping error dialog in drop-in

[OscarSpruit]

Description

1. Override this in the drop in service:

override fun onBalanceCheck(paymentComponentState: PaymentComponentState<*>) {
    val result = handleBalanceResponse(null)
    sendBalanceResult(result)
}

2. Open drop-in
3. Do a gift card payment
4. Aaaand you're now stuck on a loading state with an error dialog behind it...

The issue is fixed by using showNow() when showing the loading state fragment. An extra improvement is to always dismiss the loading state when we get back a result from the merchant. Before we only dismissed the loading state in some specific places.

Checklist

• PR is labelled
• Changes are tested manually

COAND-984

[github-actions]

✅ No public API changes

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud