Adds logging for Launcher restore metrics in Launcher and LoaderTask

- Adds flag for indicating when we are loading after a restore, separate from the pending restore flag
- Adds many success/failure scenario metrics when loading and binding items

Flag: ACONFIG enable_launcher_br_metrics DEVELOPMENT
Test: locally verified
Bug: 307527314
Change-Id: I9d2660f6d9d7cd5813072201e96b1a64aec4ea4b