Prepare app_inst_req for handling multiple app_ids at once

Prepare app_inst_req for handling multiple app_ids at once

Application install and uninstall requests will enable support for
handling multiple app_ids from single package in one shot.
The app_inst_req structure is modified to include an array of application
parameters, i.e.:
- app_id
- privileges
- app defined privileges

To make use of this feature, a new API will be added in next commits.
For now the modified request data structure will serve the existing API,
holding only single element in array of app parameters.

Change-Id: If961ad3625f9397358487021982f07886cee1e28
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>