[CCT][ToolbarRefactor] Prevent minimize button from showing in PCCT

After the last CL, the minimize button was shown on the PCCT toolbar.
This CL makes sure we hide the minimize button if it's been previously
inflated but should be gone.

Bug: 402213312
Change-Id: I01d022355014e37422b7444b8200bd1f92590109
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6527167
Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/main@{#1458212}