Fix kfp-kubernetes-library-tests by regenerating Python protobuf bindings

- Regenerate Python protobuf bindings to include the optional field for SecretAsEnv and ConfigMapAsEnv
- Update test_volume.py to expect optional: False in secretAsEnv
- Include backend driver code that handles optional field (from stash)
- All 110 kfp-kubernetes-library-tests now pass
- Fixes PR kubeflow#12216 test failures

Signed-off-by: ddalvi <[email protected]>

Author: DharmitD

backend/src/v2/driver/k8s.go

@@ -273,11 +273,13 @@ func extendPodSpecPatch(
 	// Get secret env information
 	for _, secretAsEnv := range kubernetesExecutorConfig.GetSecretAsEnv() {
 		for _, keyToEnv := range secretAsEnv.GetKeyToEnv() {
+			optional := secretAsEnv.Optional != nil && *secretAsEnv.Optional
 			secretEnvVar := k8score.EnvVar{
 				Name: keyToEnv.GetEnvVar(),
 				ValueFrom: &k8score.EnvVarSource{
 					SecretKeyRef: &k8score.SecretKeySelector{
-						Key: keyToEnv.GetSecretKey(),
+						Key:      keyToEnv.GetSecretKey(),
+						Optional: &optional,
 					},
 				},
 			}