Revert "Phone Hub: Modify Phone Hub tray to show nudge."

This reverts commit cfaa8128.

Reason for revert: causing crash see b/273532240

Original change's description:
> Phone Hub: Modify Phone Hub tray to show nudge.
>
> Modify Phone Hub tray methods to display Phone Hub nudge if nudge flag is on. Also, hide the nudge when Phone Hub icon is clicked.
>
> UI:
> (Recording of nudge being hidden after clicking on Phone Hub icon)
> https://drive.google.com/file/d/1P9yVCb-aRB7IXY2gqHhorPFXbojnpckz/view?usp=sharing
> https://screenshot.googleplex.com/6DLVFX739n9Us6a
>
> Change-Id: I81ea423963ce395521e749a96b0ac7db33474020
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4163684


> Commit-Queue: Jennifer Serrano <jennserrano@google.com>
> Reviewed-by: Jon Mann <jonmann@chromium.org>
> Reviewed-by: Alex Newcomer <newcomer@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1098164}

Bug: b/273532240

Change-Id: I9e5a60fc2d39926e211a6eaf312596dc67fd7f11
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4347815


Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Jon Mann <jonmann@chromium.org>
Commit-Queue: Jennifer Serrano <jennserrano@google.com>
Reviewed-by: Pu Shi <pushi@google.com>
Cr-Commit-Position: refs/heads/main@{#1118820}