Android Firebase Analytics Custom Events Reporting in Console

First, credit to AdamK for adding this:

Custom parameters: Custom parameters are not represented directly in your Analytics reports, but they can be used as filters in audience definitions that can be applied to every report. Custom parameters are also included in data exported to BigQuery if your app is linked to a BigQuery project.

But, something I discovered is:

which would explain why my custom parameters do not appear as I am the only tester.

Your data may not be displayed because you have assigned a String value to FirebaseAnalytics.Param.VALUE in the bundle.

According to the FirebaseAnalytics docs on Param.VALUE:

A context-specific numeric value which is accumulated automatically for each event type. Value should be specified with putLong(String, long) or putDouble(String, double). This is a general purpose parameter that is useful for accumulating a key metric that pertains to an event.

To log a String, you may consider using Param.CONTENT_TYPE or your own custom parameter.

As of May 2017, custom parameter reporting is now supported in Google Analytics for Firebase. Please refer to this help center article for more details.

I believe any params attached to a custom event are considered custom params (even if you use those from FirebaseAnalytics.Param class) and therefore the values are not represented directly in your reports as per the docs here:

Custom parameters: Custom parameters are not represented directly in your Analytics reports, but they can be used as filters in audience definitions that can be applied to every report. Custom parameters are also included in data exported to BigQuery if your app is linked to a BigQuery project.