I use ./gradlew assembleAndroidTest to create app-debug-androidTest.apk, but the versionCode for apk is always 0. Is there any to set the versionCode for app-debug-androidTest.apk. 
Thanks!
For normal apk, I can set in AndroidManifest.xml:
android:versionCode="110"
android:versionName="3.0.17 alpha"
or in build.gralde:
defaultConfig {
    applicationId "com.android.searchui"
    minSdkVersion 18
    targetSdkVersion 22
    versionCode 84
    versionName "9.4"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
But when during instrumented tests, there are generated two .apk files. And the smaller one is app-debug-androidTest-unaligned.apk and it's versionCode is 0.
Updated on 2017/8/4:
I think it's very difficult to do this because the com.android.application gradle plugin didn't provider androidTest apk versionCode setting.
So I just put a version.xml to src/androidTest/res/values folder:
<resources>
    <integer name="versionCode">111</integer>
</resources>
Use this to fake versionCode.