Nativescript-plugin-firebase: Validation for analytics event key seems incorrect

[s-ovation]

According to the comment in analytics-common.ts and also official document: https://firebase.google.com/docs/reference/cpp/group/parameter-names, alphanumeric characters are allowed in param names.

However, the regexp used in the following line does not accept 'numeric' character.

https://github.com/EddyVerbruggen/nativescript-plugin-firebase/blob/6a2e0a9f1aeb26f6e568c3e68bd960069f4fe150/src/analytics/analytics-common.ts#L12

So, a param name like 'group1' is rejected by the logic.

[EddyVerbruggen]

Damn, you're right. Let me fix that. Thanks for reporting it!