UID In attrs are not supported. Instead of using the uid field in attrs you can use the computed field.

Solutions.

1. You can use a compute field to update the current user id and compare it in attrs

manager_id = fields.Integer(compute='get_current_uid', string='Manager ID Computed')

def get_current_uid(self):
 """
 
 :param self: 
 :return: 
 """
    if self.env.context.get('uid', False):
       self.manager_id = self.env.context.get('uid', False)
    else:
       self.manager_id = False

​attrs = "{'invisible': [('state', 'in', ['draft', 'approved', 'rejected']), ('manager.id', '=', computed_field)]}"

2. In ODOO this function(overrided and updated) allows getting uid in attrs.

# Don't deal with groups, it is done by check_group().
# Need the context to evaluate the invisible attribute on tree views.
# For non-tree views, the context shouldn't be given.
def transfer_node_to_modifiers(node, modifiers, context=None, in_tree_view=False):
    if node.get('attrs'):
        if 'uid' in node.get('attrs'):
            if context.get('uid', False):
                user_id = str(context.get('uid', False))
                attrs = node.get('attrs')
                node.set('attrs', attrs.replace('uid', user_id))
            else:
                user_id = '1'
                attrs = node.get('attrs')
                node.set('attrs', attrs.replace('uid', user_id))
        modifiers.update(eval(node.get('attrs')))
    if node.get('states'):
        if 'invisible' in modifiers and isinstance(modifiers['invisible'], list):
            # TODO combine with AND or OR, use implicit AND for now.
            modifiers['invisible'].append(('state', 'not in', node.get('states').split(',')))
        else:
            modifiers['invisible'] = [('state', 'not in', node.get('states').split(','))]

    for a in ('invisible', 'readonly', 'required'):
        if node.get(a):
            v = bool(eval(node.get(a), {'context': context or {}}))
            if in_tree_view and a == 'invisible':
                # Invisible in a tree view has a specific meaning, make it a
                # new key in the modifiers attribute.
                modifiers['tree_invisible'] = v
            elif v or (a not in modifiers or not isinstance(modifiers[a], list)):
                # Don't set the attribute to False if a dynamic value was
                # provided (i.e. a domain from attrs or states).
                modifiers[a] = v