Do not exit the GLSurfaceView thread when detached from a window.

Allows a GLSurfaceView to be removed from a window and later reattached
to a window.

Change-Id: I2b44f35d0c95404b13912782df8877953609a5d0

opengl/java/android/opengl/GLSurfaceView.java

@@ -530,7 +530,6 @@ public class GLSurfaceView extends SurfaceView implements SurfaceHolder.Callback
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
-        mGLThread.requestExitAndWait();
     }
 
     // ----------------------------------------------------------------------