GitLab

If the already existing filesystem encompasses the entire /data partition
and does not leave the last 16 Kbytes for the crypto footer, refuse to
do encrypt in place and return an error.  This is only an issue for folks
with early development systems trying to encrypt an old /data.  This should
not be seen in released devices.

Also, if there is an error, try to report back to the UI what the error was
so it can deal with it.

Change-Id: If66781a4fe03034c96c3dd12075240deb8663db0