game_engine. Fix an issue in java game engine.

If the game bundle is null, do not attempt to get data from the bundle.
This scenario is expected to happen in unit and system testing.
game_engine. Fix bugs in os memory buffer.

Remove call to resize from constructor, add a method to calculate capacity from size, and call the allocator directly from the construcotr.
Change reisze to call the capacity calculator method.
When resizing to a smaller capacity only copy data from origianl buffer that fits in the new lower sized buffer.
game_engine. Memory buffer bug fixes.

Memory buffer constructor - initialize capacity in initializer.
Fix issues in memory buffer tests
- When testing memory buffer access, checkt get function does not return NULL.
- When testing memory buffer access full buffer data, test only the data size set so far, and not full memory buffer capacity.
- Fix test memory buffer overflow test.