Our sgdisk calls are putting extra double-quotes around the names of
partitions. This confuses sfdisk, which confuses growpart, which
confuses growroot ... and you don't get your partition grown for EFI
boot.
Ensure we just bunch arguments into the list directly (for Popen)
rather than string split and have to worry about quoting. Add a check
for this to our GPT unit test, extending it to include a space in the
name of the root partition.
Change-Id: I0a8cb69bb4c9c0865fbaa63ba0d7210028da552e
b0da703f46