IndexOutOfBoundsException observed in ProcessStats

When the process dead, IndexOutOfBoundsException observed in ProcessStats
https://code.google.com/p/android/issues/detail?id=223791&thanks=223791&ts=1474967996

Change-Id: Idbe4adf060c6898e838b5eaeecf476ba6c3e586d
Signed-off-by: pengzhicai <pengzhicai@xiaomi.com>

core/java/com/android/internal/app/procstats/ProcessState.java

@@ -379,7 +379,7 @@ public final class ProcessState {
 
     public void setState(int state, long now) {
         ensureNotDead();
-        if (mCurState != state) {
+        if (!mDead && (mCurState != state)) {
             //Slog.i(TAG, "Setting state in " + mName + "/" + mPackage + ": " + state);
             commitStateTime(now);
             mCurState = state;