Update swift client + android realtime timestamp type

Author: abnegate

templates/android/library/src/main/java/io/appwrite/models/RealtimeModels.kt.twig

@@ -23,7 +23,7 @@ open class RealtimeResponse(
 data class RealtimeResponseEvent<T>(
     val events: Collection<String>,
     val channels: Collection<String>,
-    val timestamp: Long,
+    val timestamp: String,
     var payload: T
 )
 

templates/swift/Sources/Models/RealtimeModels.swift.twig

@@ -24,13 +24,13 @@ public class RealtimeCallback {
 public class RealtimeResponseEvent {
     public let events: [String]?
     public let channels: [String]?
-    public let timestamp: Int64?
+    public let timestamp: String?
     public var payload: [String: Any]?
 
     init(
         events: [String],
         channels: [String],
-        timestamp: Int64,
+        timestamp: String,
         payload: [String: Any]
     ) {
         self.events = events