Events with no parameters should be supported

[RandomShaper]

Events like the predefined tutorial_begin have no arguments, so they can be logged with a null Bundle, but this check is preventing it:

godot-android-plugin-firebase/src/main/java/org/godotengine/androidplugin/firebase/Firebase.java

Line 246 in 6f1a46f

if (key.length() <= 0 || data.size() <= 0) {

My workaround so far is sending a dummy Dictionary, like { "_": "" }.

Ideally, the method should allow null and empty Dictionary.