Signal billing_resume is not registered for this plugin.

[Chris]

Hello,
I compiled version 1.1.1 using latest master

My app crash as soon as it's launched;
I found this cause:

Caused by: java.lang.IllegalArgumentException: Signal billing_resume is not registered for this plugin.
	at org.godotengine.godot.plugin.GodotPlugin.emitSignal(GodotPlugin.java:327)
	at org.godotengine.godot.plugin.googleplaybilling.GodotGooglePlayBilling.onMainResume(GodotGooglePlayBilling.java:283)
	at org.godotengine.godot.Godot.onResume(Godot.java:876)

so I'm currently commenting the line which emits the signal: https://github.com/godotengine/godot-google-play-billing/blob/adfcef8522/godot-google-play-billing/src/main/java/org/godotengine/godot/plugin/googleplaybilling/GodotGooglePlayBilling.java#L283

I can now proceed with the billing flow, so it's a workaround for me now, but there should be a fix I think;

[Alexey Khoroshavin]

PR for this : #30