Native showcase CI tests don't run certain showcase tests

[ldetmer]

Certain showcase tests are being excluded from the native showcase CI tests. Example: EchoClientHttpJsonTest and ComplianceClientTest

If you look at this CI showcase build it includes these tests and it uses the command

 mvn verify \
    -P enable-integration-tests \
    --batch-mode \
    --no-transfer-progress

If you look at this native CI build it does not include these test. Command below:

mvn test -Pnative,-showcase -ntp -B