This is the build that should pass: https://travis-ci.org/openmrs/openmrs-contrib-android-client/builds/518355561
Another issue pops up which seems to be related to AndroidX:
ERROR: [TAG] Failed to resolve variable '${project.groupId}'
I created the issue on JIRA. GSoC aspirants, do check it and give feedback if you want.
P.S. I’m sorry for the delay, I usually reply in 2 days at the very latest. I didn’t expect 1 university programme can take away that much time (it’s finished now).