[Fix] Fetch proper app_id for creation of cgroup.

[Fix] Fetch proper app_id for creation of cgroup.

Description: The app_id was not extracted properly from procfs.
Some processes run with help of other daemons, for example
org.tizen.browser app is execued using efl_webprocess.

In this patch for resolving above issue,
if /proc/<pid>/attr/current file contains "User::Pkg::" wildcard string,
then we extract app_id from above file.
Otherwise we read /proc/<pid>/cmdline and fetch process_name as app_id.

Change-Id: I0eb46f4f675cec3f2323c0ab05388fec46c7781f
Signed-off-by: Nishant Chaprana <n.chaprana@samsung.com>