Set default value to TektonConfig object

Currently when running the Tekton operator if the controller pod is up
and webhook pod is not ready the controller will create the TektonConfig
object and that TektonConfig object will not have any default values.

This PR add the default values to TektonConfig object whenever the CR
get's created by the Controller so that even if the webhook pod is not
ready the TektonConfig CR can still have the default values.

pkg/reconciler/shared/tektonconfig/tektonconfig.go

@@ -108,6 +108,8 @@ func (r *Reconciler) ReconcileKind(ctx context.Context, tc *v1alpha1.TektonConfi
 		return nil
 	}
 
+	tc.SetDefaults(ctx)
+
 	if err := r.extension.PreReconcile(ctx, tc); err != nil {
 		// If prereconcile updates the TektonConfig CR, it returns an error
 		// to reconcile