Revert "Hide vmservice.cc behind PRODUCT macro."
Revert "Hide vmservice.cc behind PRODUCT macro."

This reverts commit 1def1f5007dcaf7880ab3fda166fa72de8359b43.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Hide vmservice.cc behind PRODUCT macro.
> 
> This removes vmservice.cc from the flutter engine release binary, which saves a few kB.
> 
> Tested using tools/test.py in product mode. Verified the binary savings using run_binary_size_analysis.py
> 
> Bug: https://github.com/dart-lang/sdk/issues/34895
> Change-Id: I74d50d3e177842310e488072f35bc11d1c597036
> Reviewed-on: https://dart-review.googlesource.com/c/84683
> Reviewed-by: Ryan Macnak <rmacnak@google.com>
> Commit-Queue: Liam Appelbe <78c2029e58e395825ba7228e218c841bb436a9e9@google.com>

TBR=rmacnak@google.com,asiva@google.com,78c2029e58e395825ba7228e218c841bb436a9e9@google.com

Change-Id: I5df5882c8f4ec46480a89c2a6549e69ed83f5a2c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: https://github.com/dart-lang/sdk/issues/34895
Reviewed-on: https://dart-review.googlesource.com/c/84832
Reviewed-by: Liam Appelbe <78c2029e58e395825ba7228e218c841bb436a9e9@google.com>
Commit-Queue: Liam Appelbe <78c2029e58e395825ba7228e218c841bb436a9e9@google.com>

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