Added udevadm settle before parted commands

* udevadm settle waits until udev event queue is handled
  so as to avoid udev race. see for example
  http://rwmj.wordpress.com/2012/01/19/udev-unexpectedness/

Closes-Bug: 1375481
Change-Id: I9598f66a8477599959cebf89d1299a30f73a6fbb
Merge "Added udevadm settle before parted commands"