SoundPool itself also creates a thread, which was called "SoundPoolThread", unrelated to the SoundPoolThread class. The SoundPoolThread class then created an unnamed thread, which showed up as "android:unnamed_thread". That's confusing, so this change renames the SoundPool thread to "SoundPool" and then names the SoundPoolThread thread as "SoundPoolThread". Say that ten times fast :)
Change-Id: I67b7e644a30c94b6eda44bf970764a52a1c2958b
