Shorten thread names

prctl(PR_SET_NAME) limits to 15 characters.  Before we had names like
"Binder Thread #" and the counter was cut off :-( Also remove redundant
"thread" at end of name; it's always a thread.

Change-Id: I1f99c2730ba0787ed9b59c15914356cddf698e2f
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 74c97ed..4890f05 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -370,7 +370,7 @@
         android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
         pid_t tid;
         if (t != 0) {
-            t->run("AudioTrackThread", ANDROID_PRIORITY_AUDIO);
+            t->run("AudioTrack", ANDROID_PRIORITY_AUDIO);
             tid = t->getTid();  // pid_t is unknown until run()
             ALOGV("getTid=%d", tid);
             if (tid == -1) {