Request a range of 100gb to 200gb for virt-hp root partition

I can't make much sense out of how partman is handling the mins and maxes...
it's tending to either give me a teeny, tiny partition or to ignore
the max size and just use the mimumum.  So, at this point I'll be happy
if it picks /anything/ between 100 and 200g.

Change-Id: If26dbf7f269fccf6ee799d0bde25976cbba89560
Merge "Request a range of 100gb to 200gb for virt-hp root partition" into production