Allow multiple close transactions for task view

This is something that can happen, so we should support it rather
than throwing an illegal state exception.

This CL just creates a new pending transaction for the close/hide
request and adds it to the list.

Test: None - there is no way to reproduce this bug, this is a blind
             fix
Bug: 288508212
Change-Id: I0264d06c7b5598a892f40cde637eff06c083ce8b