chore: re-enable java-vertexai integration tests (#11575)

Follow up of #11550

Author: diegomarquezp

.kokoro/common.sh

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-excluded_modules=('gapic-libraries-bom' 'google-cloud-jar-parent' 'google-cloud-pom-parent' 'java-vertexai')
+excluded_modules=('gapic-libraries-bom' 'google-cloud-jar-parent' 'google-cloud-pom-parent')
 
 function retry_with_backoff {
   attempts_left=$1