Test for app_add_friend() changed - friends should be made even with nonexisting...

Test for app_add_friend() changed - friends should be made even with nonexisting friend. Test for app_enalble_permissions() changed - without persistent mode rule file should exist but rules should not be written to that file.

[Issue#]        SSDWSSP-260
[Bug/Feature]   Fix libprivilege-control tests
[Cause]         N/A
[Solution]      N/A
[Verification]  Run privilege_control11_app_enable_permissions and privilege_control14_app_add_friend libprivilege-control tests (should pass)

Change-Id: I6d893de9e5060e69f8a851cd9791644e228770a9