Revert "[infra] Temporarily disable Windows SDK builder on CQ"
Revert "[infra] Temporarily disable Windows SDK builder on CQ"

This reverts commit 7594c1543f53ce3ccef9b3d868e5db2b8f00ccd0.

Reason for revert: https://crbug.com/830533 has been fixed and the
windows bots are back again.

Original change's description:
> [infra] Temporarily disable Windows SDK builder on CQ
> 
> TBR=whesse@google.com
> 
> Change-Id: I348d14b021fc7fc859dec39e88de4e3876385c7a
> Reviewed-on: https://dart-review.googlesource.com/50180
> Reviewed-by: Alexander Thomas <29642742b6693024c89de8232f2e2542cf7eedf7@google.com>

TBR=whesse@google.com,29642742b6693024c89de8232f2e2542cf7eedf7@google.com

Change-Id: I50c24d65a96f8f45b0ee2b821176a00c61998590
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/50241
Reviewed-by: Alexander Thomas <29642742b6693024c89de8232f2e2542cf7eedf7@google.com>
Commit-Queue: Alexander Thomas <29642742b6693024c89de8232f2e2542cf7eedf7@google.com>

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