Fix missing trailing commas for modal dialogs

Trailing commas were accidentally removed from the 'classes' attribute
of the table actions for the Create Property and the Create Volume Type
Extra Spec dialogs. This caused the dialogs to lose the modality.

This submit fixes the problem on the two dialogs.

Change-Id: Id2c2d1f8354e95016dc121d1143a6ea5b4460de1
Closes-Bug: #1362704
Merge "Fix missing trailing commas for modal dialogs"