Improve logging for failed scenario in staged install flow

The failure reason added to the session object disappears due to
fs-checkpointing. As a result we cannot figure out the failure reason
using dumpsys.

If we log the failure reasons, then when somebody logcats across reboot,
they can at least see the failure reason on their screen/file. This will
make debugging easier.

Bug: 146343545
Test: builds without error
Change-Id: Id5a4f1c4751b6449388c430140bb8efd8620337e