NetApp bug fix for multibackend scenario.

The multibackend scenario using filter scheduler
did not work with NetApp drivers because of use
of FLAGS. Changed to use configuration to support
the multibackend scenario.

bug 1132637

Change-Id: I8ac5bd6d4269f703c3b3b0aa062c92f4412c25af
Merge "NetApp bug fix for multibackend scenario."