Revert "Update to the latest package:collection"
Revert "Update to the latest package:collection"

This reverts commit c612650b8cb29217557fd8e6480abef4f3f13634.

Reason for revert: Introduces a conflict in google3. Rolling separately before landing in the SDK.

Original change's description:
> Update to the latest package:collection
>
> Change-Id: I142d50798fc7b5a0d1aef93f5cad8f3bc041b9da
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/213520
> Auto-Submit: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>
> Commit-Queue: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>
> Commit-Queue: Jake Macdonald <jakemac@google.com>
> Reviewed-by: Jake Macdonald <jakemac@google.com>

TBR=jakemac@google.com,dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com

Change-Id: I8fd308f0885e8e5944865e85e79f04ce2dc09c70
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/213522
Reviewed-by: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>
Commit-Queue: Nate Bosch <dc212c74d8afde9c690fdd09e74d3e5c5d5a3de0@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk