Add real UUID support to ext4_utils.

For some unknown reason, we've always been generating the same UUID
for every single ext4 partition that we formatted.  Yikes.

Add a flag to request that a real UUID be generated when creating
filesystem.

(cherry-picked from 7538cc97e1695608123739d6ef8ff2ee1572aaec)

Bug: 19993667
Change-Id: I6f3f6aa373021cb8b6779e5354ac36436c4d98d3
7 files changed