The main issue is it looks like Java is not configured to accept the invalid ssl cert that is coming from the download location.
Exception in thread "main" java.lang.RuntimeException: javax.net.ssl.SSLException: java.security.ProviderException: java.security.InvalidKeyException: EC parameters error
export ANDROID_HOME=/home/user/Downloads/tools/
Conversations-master$ ./gradlew
Downloading https://services.gradle.org/distributions/grad........