move event log tags used by system server into this package

We can now locate event log tag definitions in individual packages
(and java constants for the tag numbers get auto-generated), so move
all the tags used by the system server into the package.
diff --git a/services/java/com/android/server/ConnectivityService.java b/services/java/com/android/server/ConnectivityService.java
index a91635e..676e5f6 100644
--- a/services/java/com/android/server/ConnectivityService.java
+++ b/services/java/com/android/server/ConnectivityService.java
@@ -56,9 +56,6 @@
     private static final boolean DBG = true;
     private static final String TAG = "ConnectivityService";
 
-    // Event log tags (must be in sync with event-log-tags)
-    private static final int EVENTLOG_CONNECTIVITY_STATE_CHANGED = 50020;
-
     // how long to wait before switching back to a radio's default network
     private static final int RESTORE_DEFAULT_NETWORK_DELAY = 1 * 60 * 1000;
     // system property that can override the above value
@@ -1230,7 +1227,7 @@
                     int eventLogParam = (info.getType() & 0x7) |
                             ((info.getDetailedState().ordinal() & 0x3f) << 3) |
                             (info.getSubtype() << 9);
-                    EventLog.writeEvent(EVENTLOG_CONNECTIVITY_STATE_CHANGED,
+                    EventLog.writeEvent(EventLogTags.CONNECTIVITY_STATE_CHANGED,
                             eventLogParam);
 
                     if (info.getDetailedState() ==