utils: Map Available to UnavailableOffline

- State `Available` will be mapped to `UnavailableOffline` for
  Status.State for resources that are present but unavailable
- Added a utility function to reduce code duplication for retrieving
  resource's Status.State (`getResourceState`) and Status.Health
  (`getResourceHealth`)

Tested:
- Compiles and builds
- Unit tests pass

Change-Id: I1164a9412cbd4e1ab8938366ffc7ea9c7fe58786
Signed-off-by: Justin Nguyen <justinnanguyen@gmail.com>