Convert lvm_mirrors to int

When the location_info is parsed and `lvm_mirrors` extracted, it is not
being converted to int. This causes some boolean checks to return True
even when there are not mirrors enabled because of the u'0'.

Closes-bug: #1258133
(cherry picked from commit 1dff30492f0ce1df3ef01ccc21353248a7207709)

Change-Id: I67c463d9f139fe326bbcab4d193c45459129b514
LVM migration: Check if name is equal to dest_vg

The existence check of the destination volume group is wrong. It
currently checks if there's a VG with a name equal to the source's vg
name instead of checking if it's equal to the dest_vg.

Closes-bug: #1258203
(cherry picked from commit 17912f4c4fba270a15cab47bb68d9e30c34a69b0)

Change-Id: Ia5d4acb24b94c6aa832107c7eb4b6996985af97f
Merge "Convert lvm_mirrors to int" into stable/havana
Merge "LVM migration: Check if name is equal to dest_vg" into stable/havana
Merge remote-tracking branch 'upstream/stable/havana' into stable/havana