Android: Removed identify and added some missing functions

**0.7**
- **Breaking change**: `identify` is no longer called automatically. If you want to use People Analytics with your own user ids, you have to call `identify` manually from now on.
- Added support for the following functions:
    - `profileTrackCharge(String name, Object properties)`
    - `profileClearCharges()`
    - `profileDeleteUser()`
    - `showSurveyById(id)`
    - `showNotificationById(id)`