fix(material/toolbar): Update icon button color to match label text color token

[amysorto]

Fixes #30279

Note: this only affects icon buttons that have the mat-unthemed class.

[richardsengers]

@amysorto what is the status of this PR? it's not yet merged in the latest release :-(

[richardsengers]

@crisbeto do you know why this PR is still open?It is a bit of a showstopper

[csvn]

I just encountered the issue this PR fixes for toolbar icons when trying to adapt the M3 theme. Is this PR being blocked by something? I can't see this fix included in any existing versions.

[mmalerba]

There are hundreds of screenshots in g3 that wind up looking worse with this change. It seems to cause the exact issue its attempting to fix in some apps, likely because they're already working around it somehow. It'll take some work to land

[ohmnoms]

You can easily handle this with a nested override:

	mat-toolbar {
		@include mat.icon-overrides(
			(
				color: map.get(map.get(themes.$primary), 94), // or however you'd get this color
			)
		);
	}

But I suppose this is just a workaround for the larger issue