Revert "Use MappedFile for mmap-related operations in CursorWindow"

This reverts commit e28dd9f756fd7df72e39260e82a7569a3636d0af.

Reason for revert: Breaks STS

Bug: 372629475
Change-Id: I708ac6e193b1b4cc0adfc0875e075fe5fd5d7191
2 files changed