[DocsUI M3] Update the error state illustration color

Use hardcoded color value for the triangle in the error state
illustration because the color attribute is not supported in
Material for now.

Check the attached bug for screenshots.

Bug: 401099647
Test: m DocumentsUIGoogle && manual inspection
Flag: com.android.documentsui.flags.use_material3
Change-Id: I9512601517f384cecf9fb64516e655a8c6bb662c