User fjckls on github posted a solution that allowed me to build, at least for now it’s an effective patch: https://github.com/arnesson/cordova-plugin-firebase/issues/1057#issuecomment-490000068
This is due to the firebase updates on April 05. Here https://firebase.google.com/support/release-notes/android#update_-_april_02_2019, I found the last working versions and adjusted my project.properties accordingly like so
cordova.system.library.4=com.google.firebase:firebase-core:16.0.8 cordova.system.library.5=com.google.firebase:firebase-messaging:17.5.0 cordova.system.library.6=com.google.firebase:firebase-config:16.4.1 cordova.system.library.7=com.google.firebase:firebase-perf:16.2.4Here all dependencies are locked to the specific version (Update - April 02, 2019) instead of
+, which would get you the latest version thus breaking the build process.Now I can build successfully! Hope it helps!
project.properties can be found on platforms/android/project.properties