Deprecate `sanitize_conditions`. Use `sanitize_sql` instead

Because `sanitize_conditions` protected method is only used in one place.

activerecord/CHANGELOG.md

+*   Deprecate `sanitize_conditions`. Use `sanitize_sql` instead.
+
+    *Ryuta Kamizono*
+
 *   Doing count on relations that contain LEFT OUTER JOIN Arel node no longer
     force a DISTINCT. This solves issues when using count after a left_joins.
 

activerecord/lib/active_record/querying.rb

@@ -62,8 +62,7 @@ def find_by_sql(sql, binds = [], preparable: nil)
     #
     # * +sql+ - An SQL statement which should return a count query from the database, see the example above.
     def count_by_sql(sql)
-      sql = sanitize_conditions(sql)
-      connection.select_value(sql, "#{name} Count").to_i
+      connection.select_value(sanitize_sql(sql), "#{name} Count").to_i
     end
   end
 end

activerecord/lib/active_record/sanitization.rb

@@ -29,8 +29,9 @@ def sanitize_sql_for_conditions(condition)
           else        condition
           end
         end
-        alias_method :sanitize_sql, :sanitize_sql_for_conditions
-        alias_method :sanitize_conditions, :sanitize_sql
+        alias :sanitize_sql :sanitize_sql_for_conditions
+        alias :sanitize_conditions :sanitize_sql
+        deprecate sanitize_conditions: :sanitize_sql
 
       # Accepts an array, hash, or string of SQL conditions and sanitizes
       # them into a valid SQL fragment for a SET clause.