ASACORE-969: PermissionMgmt Interface

Move the serialize/deserialize codes for PermissionPolicy
from class PermissionMgmtObj to PermissionPolicy so the Security
Manager codes can use them.

Change-Id: I27262d09e4ceb6b4fd0bf5cfb165dde91b9e863e
Signed-off-by: Phil Nguyen <philn@qce.qualcomm.com>