Gradle use certificate authentication for repository

The Problem

I have a Android Gradle project which should pull a lib from my companys sonatype nexus server. The nexus server uses a certificate authentication. That means the client has a private certificate which authenticates and authorizes him against the nexus server.

The problem is how to configure gradle to use my certificate (which is in the osx keystore).

/app/build.gradle

repositories {
   // some other repositorys...
   ...
   maven {
      credentials {
         username = NEXUS_USERNAME
         password = NEXUS_PASSWORD
      }
      url 'https://prefix.server.com/nexus/content/repositories/artifactid'
   }
}

Without giving a certificate the nexus server respont with:

Error: Could not HEAD 'https://prefix.server.com/nexus/content/repositories/artifactid/de/komoot/android/kmt-material-showcase/0.0.1/kmt-material-showcase-0.0.1.pom'. Received status code 400 from server: Bad Request

My first solution was to try to configure the jvm to use the osx keychain for certificates. The same method helped me to push and publish libs/artifacts on the nexus server.

/app/gradle.properties

org.gradle.jvmargs=-Djavax.net.ssl.keyStore=NONE -Djavax.net.ssl.keyStoreType=KeychainStore -Djavax.net.ssl.keyStorePassword=-

This doesn't work the gradle sync failed: Error:NONE (No such file or directory)

It looks like the gradle expected to be 'NONE' of the paramter '-Djavax.net.ssl.keyStore'. I tryed several uper and lower case solutions but all failed.

The second approach was to try it with

org.gradle.jvmargs=-Djavax.net.ssl.keyStoreType=KeychainStore

But the server respond with 400 again. Looks like the JVM args haven't been used.

Any ideas or articles for this topic ? Hope someone can help me.