Creating Fabric in Android Studio will create a "true" folder in the project root?

I am using Fabric in my project which works well. But I found the problem when I start the build, sometimes it generates a new folder named "true" in the root folder of the project which contains only one file: crashlytics-build.properties. Is this folder required? Can I change the location of the crashlytics-build.properties generation? Thank.

There are many modules in my project, this is the gradle file for the root project:

buildscript {
    repositories {
        jcenter()
        maven { url 'https://maven.fabric.io/public' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.3.1'
        classpath 'io.fabric.tools:gradle:1.+'
    }
}

allprojects {
    repositories {
        jcenter()
        maven { url 'https://maven.fabric.io/public' }
        flatDir{
            dirs '../libs'
        }
    }
}