[DocsUI, Search]: Fix testSearchV2FileTypeDropdown test.

On small screens the test fails as file type dropdown is not visible.
This fix scrolls the file type trigger into view before clicking it.

Bug: 428636317
Test: atest DocumentsUIGoogleTests
Flag: com.android.documentsui.flags.use_search_v2_read_only
Change-Id: I36df99331aaec3d19b78ad5f60b5d7af8de1f579