Add check for Environment proto field before accessing in Dataflow pr…

…ovider (#10016) (#6999)

[upstream:6aba2a9bda474112d1d59bf0b8e7b627afb2ee7a]

Signed-off-by: Modular Magician <magic-modules@google.com>

.changelog/10016.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+dataflow: fixes potential nil-pointer error if a job's Environment field is nil when reading job information in `google_dataflow_job`
+```

google-beta/services/dataflow/resource_dataflow_job.go

@@ -372,6 +372,9 @@ func resourceDataflowJobRead(d *schema.ResourceData, meta interface{}) error {
 	if err := d.Set("effective_labels", job.Labels); err != nil {
 		return fmt.Errorf("Error setting effective_labels: %s", err)
 	}
+	if job.Environment == nil {
+		return fmt.Errorf("Error accessing Environment proto: proto is nil")
+	}
 	if err := d.Set("kms_key_name", job.Environment.ServiceKmsKeyName); err != nil {
 		return fmt.Errorf("Error setting kms_key_name: %s", err)
 	}