* Remove AppDelegate memory leak from Android projects
AppDelegate object and all its members are never released.
As a solution I propose to use static unique_ptr that could destroy it
at the end of the application.
Issue:
https://github.com/cocos2d/cocos2d-x/issues/14110
* Correct code style in Android main.cpp files
- removed redundant headers (reduced dependencies)
- removed redundant code
- corrected code style
minggo