BUG_FIX: - make glClearColor be red, but not dark which is hard to identify; - add condition check in Init(), make sure app->window is not null before   run the EGL init. If app->window is null, it will bring crash when call   ANativeWindow_XXX; - make the assert be more precise - add m_bRendering to be true at the end of Init(), which will make   RenderFrame() be executable and glClear() will be run OTHER: - remove redundant LOGD
BUG_FIX:
- make glClearColor be red, but not dark which is hard to identify;
- add condition check in Init(), make sure app->window is not null before
  run the EGL init. If app->window is null, it will bring crash when call
  ANativeWindow_XXX;
- make the assert be more precise
- add m_bRendering to be true at the end of Init(), which will make
  RenderFrame() be executable and glClear() will be run
OTHER:
- remove redundant LOGD

nanayay/budding,nanayay/budding,nanayay/budding