Revert "Add CMUpdater support"

This reverts commit b54b87dc46e7de4727cfdd749aa6f50dc2c361fb.
Revert "enable SQUISHER"

This reverts commit 402c0c7c16981b6ea44cf0a0bccdc423ccc25596.
Revert "Set recovery fstab to version 2"

This reverts commit 49a7b2c3205871970706de18af6fc8650ef3f4c6.
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.