DocsUI M3: Update all tests to use the new test rule

Update all tests that were using DeviceFlagsValueProvider to use the new
CheckFlagM3.

This is a preparation to use the config force_material3 combined with
the flag use_material3.

Bug: 403375773
Test: atest DocumentsUIGoogleTests
Flag: com.android.documentsui.flags.use_material3
Change-Id: I4d626b012bc09ca0c5380abceda5f3d3356c43a7