Resolve AbuseController StrongParam rubocop exceptions

AbuseController and Admin::AbuseController both use params directly without using Rails' StrongParameters helper. This caused a Rubocop exception, which was ignored when the rubocop was introduced in !155661 (merged)

Both controllers should use strong params. In Admin::AbuseController, permitted_index_params should be defined by looking at the params utilised in app/finders/abuse_reports_finder.rb.