Update treeview expand icon

[mcoker]

Updates the tree view expand icons to point right when collapsed, down when expanded.

The core change is patternfly/patternfly#8490

Just need to update the icon from down to right.

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Jira Issue: PF-4420

[coderabbitai]

🔗 Related PRs

#12365 - chore(ArrowRightIcon): Update any uses of FA arrow right icon to RH brand arrow right icon [merged]
#12368 - chore(CaretDownIcon): Replace all usages of CaretDownIcon with RhUiCaretDownIcon [merged]
#12371 - chore(Star Icons): Replace all star FA icons with RH brand star icons [merged]
#12381 - Updated all usage of AngleDoubleLeftIcon to RhUiDoubleCaretLeftIcon [merged]
#12479 - fix(HamburgerIcon): Replace HamburgerIcon with RhUiStorageFillIcon [closed]

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