Analytics/Crash/Performance Collection enabling is unclear

[TdoubleG]

Documentation issue

It's unclear if we need to call the analytics collection on every start of the app (session based) or is it enough to enable/disable the collections only once, like the plugin stores the information about the status?

Same question for crashlytics and performance.

[dpa99c]

This is outlined in the Firebase documentation - i.e. the setting persists between sessions - but I'll add a note to the documentation to make this clearer