Description of problem:

Pipeline builder yaml view form submission, sends a POST request to an incorrect endpoint (without namespace) 

Prerequisites (if any, like setup, operators/versions):

Install Openshift pipelines 1.2

Steps to Reproduce

1. Visit Pipeline builder page and switch to yaml view
2. remove the `namespace` from the yaml content or copy paste a yaml without namespace in it.
3. Click on create button

Actual results:

creation fails with `not found` alert.

Expected results:

It should create a valid pipeline on submission.

Reproducibility (Always/Intermittent/Only Once):

Always

Build Details:

4.7.0-0.nightly-2020-12-04-013308

Additional Info:

POST request to the following endpoint

https://console-openshift-console.apps.pthangad-aws-47.qe.devcluster.openshift.com/api/kubernetes/apis/tekton.dev/v1beta1/pipelines

but it should contain namespace like below

https://console-openshift-console.apps.pthangad-aws-47.qe.devcluster.openshift.com/api/kubernetes/apis/tekton.dev/v1beta1/namespaces/karthik/pipelines