Add new API for installing pkg_id with multiple app_ids at once

Add new API for installing pkg_id with multiple app_ids at once

New client function security_manager_app_inst_req_next() enables installer
to add information about multiple applications. Each application in
request has its own app_id, privileges and app-defined privileges.
All other parameters set on the installation request are shared.

Sample usage of the new API (simplified, no error checking):

security_manager_app_inst_req_new(&p_req);

/* Per-package attributes */
security_manager_app_inst_req_set_pkg_id(p_req, pkgId);

/* Per-app attributes */
security_manager_app_inst_req_set_app_id(p_req, appId1);
security_manager_app_inst_req_add_privilege(p_req, appId1_priv1);
security_manager_app_inst_req_next(p_req);
security_manager_app_inst_req_set_app_id(p_req, appId2);
security_manager_app_inst_req_add_privilege(p_req, appId2_priv1);

security_manager_app_install(p_req);
security_manager_app_inst_req_free(p_req);

Change-Id: Ia1a42071bcf7356f17622c1d110778e803d3f39a
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>