[FIX] project: fixes 'view task' is display once the task is saved in portal

Steps to reproduce:
- Open project share any project which has task.
- My account > project > open that project you can see task .
- Open any task and add new sub-task you can see once the sub-task is saved
  'task view' button is displayed.

Issue:
- Sub-tasks notebook > add a line > 'view task' is displayed at the creation but
  is then hidden once the task is saved.

Solution:
- Correct the attrs and change the condition in able to invisible 'view task'
  once the sub-task is saved

task-3602610

closes odoo/odoo#160117

X-original-commit: cd6ed7f9fd2e0654cfb0672d7a9536dca21035cf
Signed-off-by: Xavier Bol (xbo) <xbo@odoo.com>

addons/project/views/project_sharing_project_task_views.xml

@@ -208,7 +208,7 @@
                                     <field name="stage_id" domain="[('user_id', '=', False), ('project_ids', 'in', [project_id])]"/>
                                     <button name="action_open_task" type="object" title="View Task" string="View Task" class="btn btn-link float-end"
                                             context="{'form_view_ref': 'project.project_sharing_project_task_view_form', 'search_view_ref': 'project.project_sharing_project_task_view_search'}"
-                                            invisible="project_id or project_id != id"/>
+                                            invisible="project_id != context.get('active_id')"/>
                                 </tree>
                             </field>
                         </page>