1. Prepare Pure and Bell specific `Application`
classes and add them to `app` target:
- `products/BellHybrid/apps/Application.cpp`
- `products/PurePhone/apps/Application.cpp`
2. Update `CMakeLists.txt` files.
3. Move `ApplicationBell` implementation to Bell-specific
`Application` class and remove `ApplicationBell` files.
4. Change Bell apps parent classes from `ApplicationBell`
to Bell-specific `Application` class.
5. Rename `Application` to `ApplicationCommon` in the rest of the files.
This PR provides the implementation of the auto-locking mechanism that
is dependent on an application's current auto-locking policy. Three
auto-lock policies have been introduced:
* DetermineByWindow
* DetermineByAppState
* PreventPermanently
Also changed the AutoLockWindow set/get auto-lock time value to the
message-based approach.
PhoneModeObserver doesn't work properly in applications.
Applications have to handle the phone mode changes via AppMgr.
Phone mode and tethering handlers separated.
