[DocsUI M3] Use dynamic color for Mime type icons

Since dynamic color in RRO Mime type icons is not supported
currently, as a workaround, we define a map in our app code to
achieve this custom color mapping for certain Mime type icons.

Check the attached bug for the before/after comparison.

Bug: 380746671
Test: m DocumentsUIGoogle && manual inspection
Flag: com.android.documentsui.flags.use_material3
Change-Id: Ibdfa3cc25763b6910be8cee158cc4ec912581683