Add an API for apps to get their System Health / Battery Stats data.

Change-Id: Ib27e1be469b826f6d83d73ce6024102bbdb1d47a
diff --git a/core/java/com/android/internal/os/BatteryStatsImpl.java b/core/java/com/android/internal/os/BatteryStatsImpl.java
index 60c9e14..c484121 100644
--- a/core/java/com/android/internal/os/BatteryStatsImpl.java
+++ b/core/java/com/android/internal/os/BatteryStatsImpl.java
@@ -5300,6 +5300,12 @@
         }
 
         @Override
+        public Timer getProcessStateTimer(int state) {
+            if (state < 0 || state >= NUM_PROCESS_STATE) return null;
+            return mProcessStateTimer[state];
+        }
+
+        @Override
         public Timer getVibratorOnTimer() {
             return mVibratorOnTimer;
         }