[vm] Revert service isolate setup in main.cc
[vm] Revert service isolate setup in main.cc

This CL reverts part of the
https://github.com/dart-lang/sdk/commit/e70a7aab8a60a18947c68b95189632ab6420d83a
which is related to service isolate setup in CreateAndSetupServiceIsolate.
Apparently that change caused flaky crashes/timeouts on dartkb/release bot.

Change-Id: Ibbdf89d1e461b59e41c6a8c3f98cdc8ccaedc2d1
Reviewed-on: https://dart-review.googlesource.com/c/80265
Reviewed-by: Siva Annamalai <2e618a8cbd7bb6b3d4409061ae407d692a098546@google.com>
Reviewed-by: Zach Anderson <9f8b31e960a68dade71618f1ff6da6e23a1edfc9@google.com>
Commit-Queue: Alexander Markov <239e774fd29abc1267878f57afe1a8a03e0ca887@google.com>

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