[DocsUI, Search]: Fix crash due to arg check.

SearchLoader should not be used with no limits on query. However, due to
the way MIME type filtering works (or rather does not work when asking
for /children of a folder) any MIME type filtering is consider
searching. Thus the current check is too aggressive. Removing the check
and disabling the test until proper solution is implemented.

Test: m DocumentsUIGoogle
Bug: 398759887
Flag: com.android.documentsui.flags.use_search_v2_rw
Change-Id: I262502ef5e77bb9791e6b79c188c6ab7d5904883