It worked! It finally worked! I followed the instructions in this post:
Replacing "Spark" with "Particle". Step 6 did not work (see screen shot above) so I applied the wifi settings using Putty. Later I applied different wifi settings using the Android App and it worked too.
@ScruffR , I know that most of the steps in this post were suggested by you and I had tried them, but I guess it was just a matter of doing them in the right sequence. Or maybe I was flashing the wrong cc3000. Anyway, thanks for your help and patience!