[doc]: Fix the typo of TCP UDP protocol number (sonic-net#223)

According to: https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml, the ptotocol number of TCP should be 6, and the UDP's should be 17.

documentation/general/design/dash-sonic-hld.md

@@ -262,7 +262,7 @@ key                      = DASH_ACL_RULE:group_id:rule_num ; unique rule num wit
 priority                 = INT32 value  ; priority of the rule, lower the value, higher the priority
 action                   = allow/deny
 terminating              = true/false   ; if true, stop processing further rules
-protocols                = list of INT ',' separated; E.g. 6-udp, 17-tcp; if not provided, match on all protocols
+protocols                = list of INT ',' separated; E.g. 6-tcp, 17-udp; if not provided, match on all protocols
 src_addr                 = list of source ip prefixes ',' separated
 dst_addr                 = list of destination ip prefixes ',' separated
 src_port                 = list of range of source ports ',' separated