Remove Replication.equals() and hashCode() implementation

Instead of implementing equals() amd hostCode(), just use remoteCheckpointDocID() directly.

#1386

Author: pasin

src/main/java/com/couchbase/lite/Database.java

@@ -2417,9 +2417,13 @@ private boolean postChangeNotifications() {
 
     protected Replication findActiveReplicator(Replication replicator) {
         synchronized (activeReplicators) {
-            for (Replication active : activeReplicators) {
-                if (active.equals(replicator) && active.isRunning())
-                    return active;
+            String remoteCheckpointDocID = replicator.remoteCheckpointDocID();
+            if (remoteCheckpointDocID == null)
+                return null;
+
+            for (Replication r : activeReplicators) {
+                if (remoteCheckpointDocID.equals(r.remoteCheckpointDocID()) && r.isRunning())
+                    return r;
             }
         }
         return null;

src/main/java/com/couchbase/lite/replicator/Replication.java

@@ -464,7 +464,8 @@ protected void setLastError(Throwable lastError) {
     /**
      * Following two methods for temporary methods instead of CBL_ReplicatorSettings implementation.
      */
-    protected String remoteCheckpointDocID() {
+    @InterfaceAudience.Private
+    public String remoteCheckpointDocID() {
         return replicationInternal.remoteCheckpointDocID();
     }
 
@@ -938,19 +939,4 @@ private void addProperties(ReplicationInternal replicationInternal) {
     public String toString() {
         return "Replication{" + remote + ", " + (isPull() ? "pull" : "push") + '}';
     }
-
-    @Override
-    public int hashCode() {
-        return replicationInternal.remoteCheckpointDocID().hashCode();
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (obj instanceof Replication) {
-            Replication replication = (Replication)obj;
-            return this.replicationInternal.remoteCheckpointDocID().equals(
-                    replication.replicationInternal.remoteCheckpointDocID());
-        }
-        return false;
-    }
 }