Revert "Revert "Enable color resources loader to be created usin..."

Revert submission 30159224-revert-29910507-launcher-color-preview-fix-XVTAANIJBS

Reason for revert: Bringing back original change with screenshot test
fixes, by keeping both the old color override solution using ARSC file
manipulation, and the new color override solution using fabricated
runtime resource overlays. Keep the old solution for screenshot tests,
and use the new solution for the Customization Picker use case and other
use cases needing to overlay private Android resources in a specific
context.

Reverted changes: /q/submissionid:30159224-revert-29910507-launcher-color-preview-fix-XVTAANIJBS

Flag: com.android.systemui.shared.new_customization_picker_ui
Test: manually verified
Bug: 377545987
Change-Id: Ia34ac28b79bb6b79cb7459e8326f9fa0ea59b65c