Fix HardwareManager loading order bug

The agent attempts to sort the HardwareManager implementations found
by stevedore in order of suitability. This patch fixes a bug in the
sorting order that caused the GenericHardwareManager to always be
loaded.

Fixes bug 1327923

Change-Id: I1cc20e5351a704325f0cf41dab205c9164799f6a
Merge "Fix HardwareManager loading order bug"