Revert "enable SQUISHER"

This reverts commit 402c0c7c16981b6ea44cf0a0bccdc423ccc25596.
Revert "Better description for the format of recovery.fstab."

This reverts commit 7ce3f665a850a889e0ab3f6f0dd19194fe08541c.
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.