Make racy Darwin test less racy. (#27826)

We used a 1s min-interval and a 1s sleep to wait for reports.  Those could race
very easily.  Better to use a sleep longer than the min-interval.

Fixes #27507

Author: bzbarsky-apple

src/darwin/Framework/CHIPTests/MTRXPCListenerSampleTests.m

@@ -1686,7 +1686,7 @@ - (void)test900_SubscribeClusterStateCache
 
     MTRClusterStateCacheContainer * clusterStateCacheContainer = [[MTRClusterStateCacheContainer alloc] init];
     NSLog(@"Setting up attribute cache subscription...");
-    __auto_type * params = [[MTRSubscribeParams alloc] initWithMinInterval:@(1) maxInterval:@(60)];
+    __auto_type * params = [[MTRSubscribeParams alloc] initWithMinInterval:@(0) maxInterval:@(60)];
     [device subscribeWithQueue:queue
         params:params
         clusterStateCacheContainer:clusterStateCacheContainer