Use self.configuration to support the multi-backend case

Use self.configuration instead of using FLAGS directly to make
the driver work in a multi backend environment.
And remove three repeated lines:en = out.split('\r\n')

Fixes bug: 1154125

Change-Id: I6e08706104eabb71677ec8583b9abb9711553504
Merge "Use self.configuration to support the multi-backend case"