Prefer has_report? and contains_records? from MiqReportResult

These are new methods added in:

ManageIQ/manageiq#17590

And are for more efficient for the use cases of ChargebackController and
ReportController::SavedReports.

app/controllers/chargeback_controller.rb

@@ -345,17 +345,16 @@ def cb_rpts_fetch_saved_report(id)
       @report_result_id = session[:report_result_id] = rr.id
       session[:report_result_runtime]  = rr.last_run_on
       if rr.status.downcase == "complete"
-        @report = rr.report_results
         session[:rpt_task_id] = nil
-        if @report.blank?
+        unless rr.has_report?
           @saved_reports = cb_rpts_get_all_reps(rr.miq_report_id.to_s)
           rep = MiqReport.find_by_id(rr.miq_report_id)
           if x_active_tree == :cb_reports_tree
             self.x_node = "reports-#{rep.id}"
           end
           return
         else
-          if @report.contains_records?
+          if rr.contains_records?
             @html = report_first_page(rr) # Get the first page of the results
             unless @report.graph.blank?
               @render_chart = true

app/controllers/report_controller/saved_reports.rb

@@ -35,10 +35,9 @@ def fetch_saved_report(id)
 
     return unless rr.status.downcase == "complete"
 
-    @report = rr.report_results
     session[:rpt_task_id] = nil
 
-    if @report.blank?
+    unless rr.has_report?
       add_flash(_("Saved Report \"%{time}\" not found, Schedule may have failed") %
                 {:time => format_timezone(rr.created_on, Time.zone, "gtl")},
                 :error)
@@ -56,7 +55,7 @@ def fetch_saved_report(id)
       return
     end
 
-    unless @report.contains_records?
+    unless rr.contains_records?
       add_flash(_("No records found for this report"), :warning)
       return
     end