[vm] Mark enum_private_test/01 as flaky.
[vm] Mark enum_private_test/01 as flaky.

Change-Id: I1d5b597f051808f4ef5dfbe5cc5a8e4bf77016b5
Reviewed-on: https://dart-review.googlesource.com/c/84533
Reviewed-by: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>

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