DocsUI M3: Fix M3 prefix in some material3 resources

The script used to update the IDs ignored the resource files without the
_m3 prefix. This CL fixes that.

Bug: 414914819, 403375773
Test: m DocumentsUIGoogle
Flag: com.android.documentsui.flags.use_material3
Change-Id: Ie7b53a3a103c3dc477b47e9738060a44f7974663