Android Test running failed : No Test results

You're entirely set up using AndroidX for testing, except for the test orchestrator. Instead of removing the test orchestrator (which is very useful), change

execution 'ANDROID_TEST_ORCHESTRATOR'

to

execution 'ANDROIDX_TEST_ORCHESTRATOR'

Updating my Android Studio to version 3.3 AND removing

testOptions {
    execution 'ANDROID_TEST_ORCHESTRATOR'
}

worked