@Input
  @Optional
  public Property<String> getConfigurationName() {
    String property = System.getProperty(PropertyNames.CONFIGURATION_NAME);
    if (property != null && !property.equals(configurationName.get())) {
      configurationName.set(property);
    }
    return configurationName;
  }
Returns the configurationName property while setting it to the value of the system property if
present.

@return The configurationName property
jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibExtension.java