Fix ContextMenuUiTest#testContextMenu_onArchive_shouldHaveBrowseMenuItem

These UI tests are currently only behind the `zip_ng_ro` flag, however,
the flag also gates on the `use_material3` flag. Unfortunately on some
devices without the `use_material3` flag check, the value is forced off
by the RRO. To ensure the tests run in their appropriate environment,
ensure the test is also gated behind the `use_material3` flag.

Bug: 428400255
Test: atest DocumentsUIGoogleTests:com.android.documentsui.ContextMenuUiTest
Flag: com.android.documentsui.flags.use_material3
Flag: com.android.documentsui.flags.zip_ng_ro
Change-Id: I9a7af6bb659271a55c64ddb01fc5dfb59517b5a0