bump benchmark timeouts (#16817)

dev/devicelab/lib/tasks/microbenchmarks.dart

@@ -14,7 +14,7 @@ import 'package:flutter_devicelab/framework/ios.dart';
 import 'package:flutter_devicelab/framework/utils.dart';
 
 /// The maximum amount of time a single microbenchmark is allowed to take.
-const Duration _kBenchmarkTimeout = const Duration(minutes: 6);
+const Duration _kBenchmarkTimeout = const Duration(minutes: 10);
 
 /// Creates a device lab task that runs benchmarks in
 /// `dev/benchmarks/microbenchmarks` reports results to the dashboard.

dev/devicelab/manifest.yaml

@@ -332,6 +332,7 @@ tasks:
       Runs end-to-end Flutter tests on iOS.
     stage: devicelab_ios
     required_agent_capabilities: ["mac/ios"]
+    timeout_in_minutes: 20
 
   ios_sample_catalog_generator:
     description: >