[vm] Mark some service tests as slow.
[vm] Mark some service tests as slow.

Change-Id: Ib459a8bc373a5c7090ce22b78574632dda9470b9
Reviewed-on: https://dart-review.googlesource.com/c/86205
Commit-Queue: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>
Commit-Queue: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>
Auto-Submit: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>
Reviewed-by: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk