[HACK]fs_mgr+init: Format via recovery if encryptable /data is wiped

If the encryptable partition is wiped (4KB worth of 0 or 0xff),
then reboot into recovery to format /data+/cache

This is while waiting for the Mac OS support to format f2fs.
The flashstation running on Mac OS will currently just erase userdata
and not format it with f2fs.

Bug: 15720406
Bug: 15747366
Change-Id: Ib7cca3e1701483a09573457a835750f34da71ee0