ipynb: update cgroups example to work on Android devices
ipynb: update cgroups example to work on Android devices

This version fixes issues related to execution on Android targets
by taking advantages from the new devlib's CGroup API.
The code provides also a commented version for execution on a
Juno's target running a standard Linux kernel.

Signed-off-by: Patrick Bellasi <431c86f368affbc3148c4669fbd465131f7e82cb@arm.com>

bjackman/lisa,ARM-software/lisa,JaviMerino/lisa,credp/lisa,ARM-software/lisa,ARM-software/lisa,mdigiorgio/lisa,credp/lisa,arnoldlu/lisa,credp/lisa,ARM-software/lisa,arnoldlu/lisa,credp/lisa,mdigiorgio/lisa,joelagnel/lisa,joelagnel/lisa,bjackman/lisa