QA:Testcase btrfs installation on lvm

= Description = | Put btrfs filesystem on LVM

= How to test = |
 * 1) Boot the installer.
 * 2) Create /boot as ext4 and LVM. Put / as btrfs filesystem and swap on LVM.
 * 3) Ensure installation is finished successfully.

= Expected Results = |
 * 1) Mount point can be assigned to btrfs filesystem.
 * 2) Installation completes successfully.
 * 3) System starts properly with all filesystems mounted.