metrics: network: Fix/simplify rss memory test
metrics: network: Fix/simplify rss memory test

This commit removes redundant/unuseful code, also
it adapts the code according to the new changes in
network lib, furthermore it allows to work with
runc runtime.

Another addition, it fixes the information extraction
in order to get correct measurements about RSS memory.

Signed-off-by: Mario Alfredo Carrillo Arevalo <962470f5d16f97233f38b7e7baf23f990a7fbec3@intel.com>

devimc/tests,MarioCarrilloA/tests,devimc/tests,clearcontainers/tests,chavafg/tests,chavafg/tests,clearcontainers/tests,MarioCarrilloA/tests