Order Sub Metrics of Storage types in Rate editor

fixing #2799

Order Sub Metrics of Storage types in Rate editor correctly when
editing newly created Chargeback Rate in Cloud Intel -> Chargeback
-> Rates.

app/views/chargeback/_cb_rate_edit_table.html.haml

@@ -18,12 +18,13 @@
       %th= _("Fixed")
       %th= _("Variable")
   %tbody
-    - @edit[:new][:details].each_with_index do |detail, detail_index|
+    - @edit[:new][:details].sort_by { |rd| [rd[:group], rd[:description], rd[:sub_metric].to_s] }.each do |detail|
       - @cur_group = detail[:group] if @cur_group.nil?
       - if @cur_group != detail[:group]
         - @cur_group = detail[:group]
         %tr
           %td{:colspan => "10", :style => "background-color: #f5f5f5;"}  
+      - detail_index = @edit[:new][:tiers].index { |x| x.detect { |tier_hash| tier_hash['chargeback_rate_detail_id'] == detail[:id] }.present? }
       - num_tiers = @edit[:new][:tiers][detail_index].blank? ? "1" : @edit[:new][:tiers][detail_index].length.to_s
 
       %tr.rdetail{:id => "rate_detail_row_#{detail_index}_0"}