Refactoring recovery related code

In modules, we could only use Public and SystemAPI for interaction.
Refactoring to meet that criteria. This does not change any functionality.
1. Moving unsupported async Handler creation to public api
2. Getting System user handle using SystemApi

Bug: b/289203818
Test: m

Change-Id: Ib2bdfaade3a930dd549bee25b044e4f64d13f400