Increase timeout period for clone volume.

Current timeout value for clone volume in the
SolidFire driver is 20 seconds, this is fine
in many cases however there seems to be a
number of customers doing clones of
volumes >= 400G.

A populated 400G volume is taking upwards of
35 seconds to clone in some cases resulting in failure.

There's no reason not to bump this timeout value up
significantly to a worst case scenario (ie multi-terrabyte volume).

Fixes bug: 1202007

Change-Id: I98c399f5d647e14f031018f7fc1cc43bb0d94c84
(cherry picked from commit 9ce7cdbaeb73031d841cb0943ca1812b149d1c19)
Merge "Increase timeout period for clone volume." into stable/grizzly