Move load & restore logs to logging.cpp

We perform these steps to perserve the recovery logs when wiping
/cache partition. Move them to logging.cpp to keep the actually
EraseVolume function concise.

Bug: 130166585
Test: unit tests pass, mount cache and check last log after cache
Change-Id: Idc52833817a446f3a0148a3dd2112f911c9ef48d