(Really) fix LingerMonitor rate limiting

The previous patch was applied to the wrong member and did not actually
fix the issue.

Bug: b/117516272
Test: remote run passed
Change-Id: I3f9c27ebd6c339e98a71cb179b0be65950f9b864
diff --git a/services/core/java/com/android/server/connectivity/LingerMonitor.java b/services/core/java/com/android/server/connectivity/LingerMonitor.java
index 0e727c5..929dfc4 100644
--- a/services/core/java/com/android/server/connectivity/LingerMonitor.java
+++ b/services/core/java/com/android/server/connectivity/LingerMonitor.java
@@ -90,8 +90,8 @@
         mNotifier = notifier;
         mDailyLimit = dailyLimit;
         mRateLimitMillis = rateLimitMillis;
-        // Ensure that (now - mFirstNotificationMillis) >= rateLimitMillis at first
-        mFirstNotificationMillis = -rateLimitMillis;
+        // Ensure that (now - mLastNotificationMillis) >= rateLimitMillis at first
+        mLastNotificationMillis = -rateLimitMillis;
     }
 
     private static HashMap<String, Integer> makeTransportToNameMap() {