[M69 Migration][Product TV] Apply CAP-admin capability to efl_webprocess

[M69 Migration][Product TV] Apply CAP-admin capability to efl_webprocess

This patch is migrated from m63:
https://review.tizen.org/gerrit/#/c/177876/

The process privilege should be dropped when web app is launched
to support "Process Pool" feature.

In order to drop the privilege, the process should have the
cap_mac_admin capability because we cannot use the "Dyntransition"
feature of security in only product tv environment.

Change-Id: I8601d8f7c306bb333275318bef4ffd1922f1c096
Signed-off-by: ss440 <ss440.han@samsung.com>