build.gradle

...
android {
    ...
    defaultConfig {
        ...
        testInstrumentationRunner "com.jobinlawrance.appname.MockTestRunner"
    }
}
...

MockTestRunner.kt

open class MockTestRunner : AndroidJUnitRunner() {
    override fun onCreate(arguments: Bundle?) {
        StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.Builder().permitAll().build())
        super.onCreate(arguments)
    }

    override fun newApplication(cl: ClassLoader?, className: String?, context: Context?): Application {
        return super.newApplication(cl, TestHomeApplication::class.java.name, context)
    }
}