LocationManagerService: Add debug flag lookup from properties

Instead of hardcoding true/false in the code:
 setprop log.LocationManagerService DEBUG
works just fine. Or the reboot-proof version in userdebug/eng builds:
cat > /data/local.prop <<eof
log.tag.LocationManagerService=DEBUG
eof

Change-Id: If4efad1c3adc401c0cb5d1a3cc449b53224ead08
diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index 9606cf1..03b5e12 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -92,7 +92,7 @@
  */
 public class LocationManagerService extends ILocationManager.Stub {
     private static final String TAG = "LocationManagerService";
-    public static final boolean D = false;
+    public static final boolean D = Log.isLoggable(TAG, Log.DEBUG);
 
     private static final String WAKELOCK_KEY = TAG;
     private static final String THREAD_NAME = TAG;