Fix some issues with studio build

- Move private color attrs to their own resources
- Remove duplicate resource already defined in keyguard-res
  (already used elsewhere in sysui)

Bug: 152086714
Test: Studio builds
Change-Id: I4b96bedabcbe9d9c2d2f8ef394781616b83807ec
Merged-In: I4b96bedabcbe9d9c2d2f8ef394781616b83807ec
(cherry picked from commit b0d25d2e)