cgpt.py: Add size_min and fs_size_min options.

Allow specification of size_min and fs_size_min options for
partitions in disk_layout.json files, to help avoid cloning
entire layout files when needing additional space in an
overlay.

For a given layout, if both size and size_min are specified,
size becomes max(size, size_min).

BUG=None
TEST=Compare `cgpt.py debug` output before/after.

Change-Id: I2e792e0ea0b06d2b5035ebdef1749ea1dcd3ab2a
Reviewed-on: https://chromium-review.googlesource.com/344911
Commit-Ready: Josh Horwich <jhorwich@chromium.org>
Tested-by: Josh Horwich <jhorwich@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
1 file changed