DocumentsUI: Duplicate the styles, layout and theme for flag M3 enabled

This is a preparation to allow customizing the Material3 behind a flag
without changing the current layout and styles.

To see a diff of each file comparing to its original see:
http://gpaste/5094130459082752

Test: Manual build, deploy apk and start it on DUT
Flag: com.android.documentsui.flags.use_material3
Bug: 377771271
Change-Id: I38b609c7e53945bb8885e9b5dd3e58f0780830ea