pipeline: Conversion error for parameters when pipelineref.bundle is used

Webhook error messages show:

{"severity":"error","timestamp":"2022-09-15T14:38:48.420Z","logger":"tekton-pipelines-webhook","caller":"conversion/conversion.go:59","message":"Conversion failed","commit":"698f8a7-dirty","uid":"1c56f711-20c2-454d-90d1-0210280ee8f5","desiredAPIVersion":"tekton.dev/v1","error":"unable to marshal output: json: error calling MarshalJSON for type v1.ParamValue: impossible ParamValues.Type: \"\"","stacktrace":"knative.dev/pkg/webhook/resourcesemantics/conversion.(*reconciler).Convert\n\tknative.dev/pkg@v0.0.0-20220818004048-4a03844c0b15/webhook/resourcesemantics/conversion/conversion.go:59\nknative.dev/pkg/webhook.conversionHandler.func1\n\tknative.dev/pkg@v0.0.0-20220818004048-4a03844c0b15/webhook/conversion.go:64\nnet/http.HandlerFunc.ServeHTTP\n\tnet/http/server.go:2109\nnet/http.(*ServeMux).ServeHTTP\n\tnet/http/server.go:2487\nknative.dev/pkg/webhook.(*Webhook).ServeHTTP\n\tknative.dev/pkg@v0.0.0-20220818004048-4a03844c0b15/webhook/webhook.go:262\nknative.dev/pkg/network/handlers.(*Drainer).ServeHTTP\n\tknative.dev/pkg@v0.0.0-20220818004048-4a03844c0b15/network/handlers/drain.go:113\nnet/http.serverHandler.ServeHTTP\n\tnet/http/server.go:2947\nnet/http.(*conn).serve\n\tnet/http/server.go:1991"}

I believe the issue is that param value conversion doesn’t handle param type “” (i.e. param type not set-- corresponds to string type)