The interstitial is displayed repeatedly automatically.

[Torguen]

Godot version: 3.4 rc1 mono

AdMob Plugin version: 5.1.0

Issue description: When an interstitial is loaded, displayed, and closed, the interstitial continues to load and display one after another automatically. The plugin launches the signals by itself. I only configure the display of an interstitial at the beginning of the application. Then I close the interstitial tapping in the smartphone. Then the interstitial is reloaded and displayed automatically.

In the registry you can see it every time I close the interstitial. It seems that the plugin emits the "loaded" signal indefinitely. The signal should only be broadcast after the interstitial has been loaded. I'm wrong?

The expected behavior is that I close the interstitial from my smartphone and it will not be shown again automatically. The plugin should not emit the "interstitial_loaded" signal because I have not reloaded an interstitial from my code.

Could it be related to this line? https://github.com/Shin-NiL/Godot-Android-Admob-Plugin/blob/bb789e432f6a04cc8e87a9ddebd5767c862d42e6/admob-plugin/godotadmob/src/main/java/shinnil/godot/plugin/android/godotadmob/Interstitial.java#L54

[Shin-NiL]

The expected behavior is the interstitial ad is loaded automatically after closed, but not showed.