If Sun had attached a "field of use" rider to the GPLed Java there would have been unroar. It wouldn't have been GPL compatible either. It would not have been free software. However, OpenJDK was not released with any such rider. The only thing it had was an additional permission, granting proprietary Java apps explicit permission to link to the OpenJDK libraries.
Much of the JavaME specific libraries were similarly licenced as GPL, but *without* the explicit linking permission. Thus, any JavaME distributors who wished to ship proprietary apps and be *sure* to avoid the GPL, had to still get a proprietary licence from Sun. Similarly if they wished to make proprietary modifications.
So your understanding is slightly off I think. Further, the JavaME thing wouldn't have affected Google had they chosen to use OpenJDK cause I don't believe Google had or have any interest in supporting the JavaME specific APIs.