Instrument wake up reasons.

This lets us run experiments that need to know the reason for the wake
up in addition to the time and latency.

Bug: 122949636
Test: manually turning the device on and off, looking at the logs
Change-Id: I38429c3387a289010e1a2696ad351ffbe568413b
diff --git a/api/removed.txt b/api/removed.txt
index 9f4b041..262ffec 100644
--- a/api/removed.txt
+++ b/api/removed.txt
@@ -344,7 +344,7 @@
   public final class PowerManager {
     method public void goToSleep(long);
     method @Deprecated public void userActivity(long, boolean);
-    method public void wakeUp(long);
+    method @Deprecated public void wakeUp(long);
   }
 
   public class RecoverySystem {