fix: use unique timestamps for batch request

because android still needs them to be uniq

ts/session/apis/snode_api/factories/StoreGroupRequestFactory.ts

@@ -1,5 +1,5 @@
 import { UserGroupsGet } from 'libsession_util_nodejs';
-import { compact, isEmpty } from 'lodash';
+import { compact, isEmpty, uniqBy } from 'lodash';
 import { SignalService } from '../../../../protobuf';
 import { MetaGroupWrapperActions } from '../../../../webworker/workers/browser/libsession_worker_interface';
 import { GroupUpdateInfoChangeMessage } from '../../../messages/outgoing/controlMessage/group_v2/to_group/GroupUpdateInfoChangeMessage';
@@ -40,6 +40,13 @@ async function makeGroupMessageSubRequest(
     throw new Error('makeGroupMessageSubRequest: not all messages are for the same destination');
   }
 
+  const allTimestamps = uniqBy(compactedMessages, m => m.createAtNetworkTimestamp);
+  if (allTimestamps.length !== compactedMessages.length) {
+    throw new Error(
+      'tried to send batch request with messages having the same timestamp, and some platformn do not support this.'
+    );
+  }
+
   const messagesToEncrypt: Array<StoreGroupExtraData> = compactedMessages.map(updateMessage => {
     const wrapped = MessageWrapper.wrapContentIntoEnvelope(
       SignalService.Envelope.Type.CLOSED_GROUP_MESSAGE,

ts/session/conversations/ConversationController.ts

@@ -695,7 +695,7 @@ async function leaveClosedGroup(groupPk: PubkeyType | GroupPubkeyType, fromSyncM
     const createAtNetworkTimestamp = NetworkTime.now();
     // Send the update to the 03 group
     const ourLeavingMessage = new GroupUpdateMemberLeftMessage({
-      createAtNetworkTimestamp,
+      createAtNetworkTimestamp: createAtNetworkTimestamp + 1, // we just need it to be different than the one of ourLeavingNotificationMessage
       groupPk,
       expirationType: null, // we keep that one **not** expiring
       expireTimer: null,