Add example tests to CI

tools/internal_ci/linux/grpc_python_bazel_test_in_docker.sh

@@ -25,5 +25,7 @@ git clone /var/local/jenkins/grpc /var/local/git/grpc
 ${name}')
 cd /var/local/git/grpc/test
 bazel test --spawn_strategy=standalone --genrule_strategy=standalone --test_output=errors //src/python/...
+bazel test --spawn_strategy=standalone --genrule_strategy=standalone --test_output=errors //examples/python/...
 bazel clean --expunge
 bazel test --config=python3 --spawn_strategy=standalone --genrule_strategy=standalone --test_output=errors //src/python/...
+bazel test --config=python3 --spawn_strategy=standalone --genrule_strategy=standalone --test_output=errors //examples/python/...