firebase_campaign always shows (not set) value for source and medium

[mrid...@gmail.com]

I created campaign url using google-play-url-builder. And set following values :-

 Ad Network : Custom
 Application ID : [ApplicationId of My app]
 Campaign Source: test1
 Campaign Medium: email
 Campaign Term: test.

Using this URL I installed app in my android device. In Firebase console it is showing (not set)value for source(Analytics->StreamView -> Events-> Top event -> firebase_campaign -> source). 

How to get original Campaign Source(test1) in Firebase Analytics?

[Frank van Puffelen]

Also posted on https://stackoverflow.com/questions/52478687/android-app-firebase-campaign-firebase-campaign-always-shows-not-set-value-fo