Revert "free EGL resources associated to a thread when it terminates"

This reverts commit 4e620ddce344e946ced992f61a69c367ff92fe24.

reverting this commit stops applications crashing when leaving GL views.
it's most easily seen when leaving the MyTracks maps view.
eg.
  E/Adreno200-EGL( 1662): <qeglDrvAPI_eglMakeCurrent:2668>: EGL_BAD_CONTEXT
  E/libEGL  ( 1662): eglMakeCurrent:781 error 3006 (EGL_BAD_CONTEXT)
and sometimes 1000's of these until the app is destroyed
  D/OpenGLRenderer( 1310): GL error from OpenGLRenderer: 0x502
  E/OpenGLRenderer( 1310):   GL_INVALID_OPERATION

Change-Id: I6af4ad388b69184ab2d3f79c0b7ccca03acac0e1