UsageStats: Use new settings key idle_duration2 for app idle

Ignores the old, re-appropriated key "idle_duration" which is now
set to a high value in order to force disable app idle on devices
with bug b/26355386

Bug:26355386
Change-Id: Iff9de843ad6e547d29c1583687fc7f7ce7e15090
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 9a7d7bb..87922b0 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -7281,10 +7281,12 @@
          * The following keys are supported:
          *
          * <pre>
-         * idle_duration        (long)
+         * idle_duration2       (long)
          * wallclock_threshold  (long)
          * parole_interval      (long)
          * parole_duration      (long)
+         *
+         * idle_duration        (long) // This is deprecated and used to circumvent b/26355386.
          * </pre>
          *
          * <p>
diff --git a/services/usage/java/com/android/server/usage/UsageStatsService.java b/services/usage/java/com/android/server/usage/UsageStatsService.java
index c9710be..f8ed8a3 100644
--- a/services/usage/java/com/android/server/usage/UsageStatsService.java
+++ b/services/usage/java/com/android/server/usage/UsageStatsService.java
@@ -280,6 +280,11 @@
         mHandler.sendEmptyMessageDelayed(MSG_FLUSH_TO_DISK, FLUSH_INTERVAL);
     }
 
+    @Override
+    public long getAppIdleRollingWindowDurationMillis() {
+        return mAppIdleWallclockThresholdMillis * 2;
+    }
+
     private void cleanUpRemovedUsersLocked() {
         final List<UserInfo> users = mUserManager.getUsers(true);
         if (users == null || users.size() == 0) {
@@ -1107,7 +1112,13 @@
      * Observe settings changes for {@link Settings.Global#APP_IDLE_CONSTANTS}.
      */
     private class SettingsObserver extends ContentObserver {
-        private static final String KEY_IDLE_DURATION = "idle_duration";
+        /**
+         * This flag has been used to disable app idle on older builds with bug b/26355386.
+         */
+        @Deprecated
+        private static final String KEY_IDLE_DURATION_OLD = "idle_duration";
+
+        private static final String KEY_IDLE_DURATION = "idle_duration2";
         private static final String KEY_WALLCLOCK_THRESHOLD = "wallclock_threshold";
         private static final String KEY_PAROLE_INTERVAL = "parole_interval";
         private static final String KEY_PAROLE_DURATION = "parole_duration";
diff --git a/services/usage/java/com/android/server/usage/UserUsageStatsService.java b/services/usage/java/com/android/server/usage/UserUsageStatsService.java
index addb1a1..25cc13c 100644
--- a/services/usage/java/com/android/server/usage/UserUsageStatsService.java
+++ b/services/usage/java/com/android/server/usage/UserUsageStatsService.java
@@ -68,6 +68,7 @@
 
     interface StatsUpdatedListener {
         void onStatsUpdated();
+        long getAppIdleRollingWindowDurationMillis();
     }
 
     UserUsageStatsService(Context context, int userId, File usageStatsDir,
@@ -581,9 +582,11 @@
      */
     void refreshAppIdleRollingWindow(final long currentTimeMillis, final long deviceUsageTime) {
         // Start the rolling window for AppIdle requests.
+        final long startRangeMillis = currentTimeMillis -
+                mListener.getAppIdleRollingWindowDurationMillis();
+
         List<IntervalStats> stats = mDatabase.queryUsageStats(UsageStatsManager.INTERVAL_DAILY,
-                currentTimeMillis - (1000 * 60 * 60 * 24 * 2), currentTimeMillis,
-                new StatCombiner<IntervalStats>() {
+                startRangeMillis, currentTimeMillis, new StatCombiner<IntervalStats>() {
                     @Override
                     public void combine(IntervalStats stats, boolean mutable,
                                         List<IntervalStats> accumulatedResult) {