Revert "Better description for the format of recovery.fstab."

This reverts commit e8fcb10684338bb65331342904770d3a5e9746e4.
Revert "Remove the custom variant of the "ota_from_target_files" script."

This reverts commit 85c038a772cbf39f5bd9a9ba631bf25dd0f1ee14.
Revert "Convert the changes from common-ota_from_target_files.py to a device-specific hook for the "core" ota_from_target_files script."

This reverts commit bbd21082e311961d93b44de71ed1fd5f487d4d77.
Revert "Convert recovery.fstab to the "version 2" format."

This reverts commit 654bcadfb4bd5f33cc48615211539012c8b548b2.