Handle multi-user in note task initialization

* Fix bug where Note Task for Multi-Users may not be initialized.
* Fix bug where Note Task for Work Profile may not be initialized.
* Fix startActivityAsUser redundant warning.

Test: atest NoteTaskInitializerTest
Test: atest NoteTaskControllerTest
Flag: not needed
Fixes: b/282929487
Change-Id: I84a2b13c142ecbb2955964aeeca2b23f4360d512