Updated conversations policy

lib/models/server_config.dart

@@ -57,6 +57,29 @@ class ServerDataConservationPolicy {
         assert(minLikesLifetime != null);
 }
 
+class ConversationsPolicy {
+  final int minMessageLen;
+  final int maxMessageLen;
+  final List<String> allowedFilesType;
+  final int filesMaxSize;
+  final int writingEventInterval;
+  final int writingEventLifetime;
+
+  const ConversationsPolicy({
+    @required this.minMessageLen,
+    @required this.maxMessageLen,
+    @required this.allowedFilesType,
+    @required this.filesMaxSize,
+    @required this.writingEventInterval,
+    @required this.writingEventLifetime,
+  })  : assert(minMessageLen != null),
+        assert(maxMessageLen != null),
+        assert(allowedFilesType != null),
+        assert(filesMaxSize != null),
+        assert(writingEventInterval != null),
+        assert(writingEventLifetime != null);
+}
+
 class ServerConfig {
   final Version minSupportedMobileVersion;
   final String termsURL;
@@ -64,6 +87,7 @@ class ServerConfig {
   final String androidDirectDownloadURL;
   final PasswordPolicy passwordPolicy;
   final ServerDataConservationPolicy dataConservationPolicy;
+  final ConversationsPolicy conversationsPolicy;
 
   const ServerConfig({
     @required this.minSupportedMobileVersion,
@@ -72,10 +96,12 @@ class ServerConfig {
     @required this.androidDirectDownloadURL,
     @required this.passwordPolicy,
     @required this.dataConservationPolicy,
+    @required this.conversationsPolicy,
   })  : assert(minSupportedMobileVersion != null),
         assert(termsURL != null),
         assert(playStoreURL != null),
         assert(androidDirectDownloadURL != null),
         assert(passwordPolicy != null),
-        assert(dataConservationPolicy != null);
+        assert(dataConservationPolicy != null),
+        assert(conversationsPolicy != null);
 }