Update height of list-form when it is set on xxx2Many widget

The current view element is the `list-form` so it is not found. Instead we must
search from the content element of the xxx2Many widget because it replicate the
CSS rule.

Closes #14212
(grafted from 92e472849bc1bfe06e65cb05d6c1f30240e8786a)

--HG--
branch : 6.0

sao/src/view/form.js

@@ -3283,7 +3283,7 @@ function eval_pyson(value){
                 this.screen.size_limit = size_limit;
                 this.screen.display();
                 if (this.attributes.height !== undefined) {
-                    this.screen.current_view.el
+                    this.content
                         .find('.treeview,.list-form').first()
                         .css('min-height', this.attributes.height + 'px')
                         .css('max-height', this.attributes.height + 'px');
@@ -3733,7 +3733,7 @@ function eval_pyson(value){
                 }
                 this.screen.display();
                 if (this.attributes.height !== undefined) {
-                    this.screen.current_view.el
+                    this.content
                         .find('.treeview,.list-form').first()
                         .css('min-height', this.attributes.height + 'px')
                         .css('max-height', this.attributes.height + 'px');