Apply Style/SymbolProc rubocop rule

This style is much more concise.

app/controllers/admin/poll/shifts_controller.rb

@@ -36,7 +36,7 @@ class Admin::Poll::ShiftsController < Admin::Poll::BaseController
   end
 
   def search_officers
-    @officers = User.search(params[:search]).order(username: :asc).select { |o| o.poll_officer? }
+    @officers = User.search(params[:search]).order(username: :asc).select(&:poll_officer?)
   end
 
   private

app/controllers/admin/settings_controller.rb

@@ -8,7 +8,7 @@ class Admin::SettingsController < Admin::BaseController
                 :poster_feature_short_title_setting, :poster_feature_description_setting
 
   def index
-    all_settings = Setting.all.group_by { |setting| setting.type }
+    all_settings = Setting.all.group_by(&:type)
     @configuration_settings = all_settings["configuration"]
     @feature_settings = all_settings["feature"]
     @participation_processes_settings = all_settings["process"]

app/controllers/admin/site_customization/content_blocks_controller.rb

@@ -9,7 +9,7 @@ class Admin::SiteCustomization::ContentBlocksController < Admin::SiteCustomizati
   def index
     @content_blocks = SiteCustomization::ContentBlock.order(:name, :locale)
     @headings_content_blocks = Budget::ContentBlock.all
-    all_settings = Setting.all.group_by { |setting| setting.type }
+    all_settings = Setting.all.group_by(&:type)
     @html_settings = all_settings["html"]
   end
 

app/controllers/admin/system_emails_controller.rb

@@ -91,7 +91,7 @@ class Admin::SystemEmailsController < Admin::BaseController
     end
 
     def load_sample_reply
-      reply = Comment.select { |comment| comment.reply? }.last
+      reply = Comment.select(&:reply?).last
       if reply
         @email = ReplyEmail.new(reply)
       else