Hiding "Launch as Instance" if volume is not bootable.

If a volume which is not bootable, is used to create an instance
then the instance will go into 'Error' state.
The patch solves this issue by hiding the 'Launch as Instance'
button if the volume is not bootable.

Closes-Bug: #1327310

Change-Id: I3d9e7edf846fafab4e735d562c1ec72ad32fb220
Merge "Hiding "Launch as Instance" if volume is not bootable."