Remove ProximityAlerts Receiver when last ProximityAlert expires.

Remove the ProximityAlerts update Receiver when the last ProximityAlert expires.
Fixes issue 6900.

Change-Id: Ida1970c084e71df47b204c64986a065cb75d0c13
diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index e39da8c..d679a5e9 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -1202,8 +1202,9 @@
             // Remove expired alerts
             if (intentsToRemove != null) {
                 for (PendingIntent i : intentsToRemove) {
-                    ProximityAlert alert = mProximityAlerts.remove(i);
+                    ProximityAlert alert = mProximityAlerts.get(i);
                     mProximitiesEntered.remove(alert);
+                    removeProximityAlertLocked(i);
                 }
             }
         }