Only show the top 10 CPU processes (for CPU usage).

- This is similar to what we do for ANRs.
- Showing the full list just add noise to the watchdog reposts.

Change-Id: Ieca0b180d4f62e44894decf5c17a9a02b9ce103c

services/core/java/com/android/server/Watchdog.java

@@ -915,7 +915,7 @@ public class Watchdog implements Dumpable {
         // The system's been hanging for a whlie, another second or two won't hurt much.
         SystemClock.sleep(5000);
         processCpuTracker.update();
-        report.append(processCpuTracker.printCurrentState(anrTime));
+        report.append(processCpuTracker.printCurrentState(anrTime, 10));
         report.append(tracesFileException.getBuffer());
 
         if (!halfWatchdog) {