Removed collapsing toolbar from stats fragment

[nbradbury]

This PR fixes a bug introduced by #21606 which causes the stats toolbar to overlap the status bar after scrolling.

After looking into this, I decided the best fix was to simply disable the collapsing toolbar. None of the other "My Site" screens (posts, pages, Media, etc.) collapse the toolbar, so changing Stats to behave the same made sense.

To test, open stats and ensure the scrolling works as expected and doesn't cause the toolbar to overlap the status bar.

BEFORE

stats.mp4

AFTER

stats-fix.mp4

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 25.7. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by 🚫 Danger

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21611-2130f24
	Commit	2130f24
	Direct Download	wordpress-prototype-build-pr21611-2130f24.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr21611-2130f24
	Commit	2130f24
	Direct Download	jetpack-prototype-build-pr21611-2130f24.apk

Note: Google Login is not supported on these builds.