Gradle task to run androidTest after installing APKs manually

I have a requirement where i have to give permission to the App to perform testing. So I'm trying to follow this approach:

1. Generate Application and test apk with assembleAndroidTest
2. Install the Application with adb install -g App.apk
3. Install test Apk
4. Run the TCs.

now i have problem with step 4. Is there any gradle command to run the androidTests after installing application and test APKs ?