Merges HEADBANGPROTECT and EARBANGPROTECT into new secondary flag (#24881)

Unless we get a clothing item that can be worn on the head, and the
ears, and only protects from loud noises in one of the configurations,
this isn't going to be an issue.

Frees up another flag slot, all hail the secondary flags.

code/game/objects/items/devices/radio/headset.dm

@@ -42,11 +42,14 @@
 /obj/item/device/radio/headset/syndicate/alt //undisguised bowman with flash protection
 	name = "syndicate headset"
 	desc = "A syndicate headset that can be used to hear all radio frequencies. Protects ears from flashbangs. \nTo access the syndicate channel, use ; before speaking."
-	flags = EARBANGPROTECT
 	origin_tech = "syndicate=3"
 	icon_state = "syndie_headset"
 	item_state = "syndie_headset"
 
+/obj/item/device/radio/headset/syndicate/alt/Initialize(mapload)
+	..()
+	SET_SECONDARY_FLAG(src, BANG_PROTECT)
+
 /obj/item/device/radio/headset/syndicate/alt/leader
 	name = "team leader headset"
 	command = TRUE
@@ -72,10 +75,13 @@
 /obj/item/device/radio/headset/headset_sec/alt
 	name = "security bowman headset"
 	desc = "This is used by your elite security force. Protects ears from flashbangs. \nTo access the security channel, use :s."
-	flags = EARBANGPROTECT
 	icon_state = "sec_headset_alt"
 	item_state = "sec_headset_alt"
 
+/obj/item/device/radio/headset/headset_sec/alt/Initialize(mapload)
+	..()
+	SET_SECONDARY_FLAG(src, BANG_PROTECT)
+
 /obj/item/device/radio/headset/headset_eng
 	name = "engineering radio headset"
 	desc = "When the engineers wish to chat like girls. \nTo access the engineering channel, use :e. "
@@ -124,10 +130,13 @@
 /obj/item/device/radio/headset/heads/captain/alt
 	name = "\proper the captain's bowman headset"
 	desc = "The headset of the boss. Protects ears from flashbangs. \nChannels are as follows: :c - command, :s - security, :e - engineering, :u - supply, :v - service, :m - medical, :n - science."
-	flags = EARBANGPROTECT
 	icon_state = "com_headset_alt"
 	item_state = "com_headset_alt"
 
+/obj/item/device/radio/headset/heads/captain/alt/Initialize(mapload)
+	..()
+	SET_SECONDARY_FLAG(src, BANG_PROTECT)
+
 /obj/item/device/radio/headset/heads/rd
 	name = "\proper the research director's headset"
 	desc = "Headset of the fellow who keeps society marching towards technological singularity. \nTo access the science channel, use :n. For command, use :c."
@@ -143,10 +152,13 @@
 /obj/item/device/radio/headset/heads/hos/alt
 	name = "\proper the head of security's bowman headset"
 	desc = "The headset of the man in charge of keeping order and protecting the station. Protects ears from flashbangs. \nTo access the security channel, use :s. For command, use :c."
-	flags = EARBANGPROTECT
 	icon_state = "com_headset_alt"
 	item_state = "com_headset_alt"
 
+/obj/item/device/radio/headset/heads/hos/alt/Initialize(mapload)
+	..()
+	SET_SECONDARY_FLAG(src, BANG_PROTECT)
+
 /obj/item/device/radio/headset/heads/ce
 	name = "\proper the chief engineer's headset"
 	desc = "The headset of the guy in charge of keeping the station powered and undamaged. \nTo access the engineering channel, use :e. For command, use :c."
@@ -196,11 +208,14 @@
 /obj/item/device/radio/headset/headset_cent/alt
 	name = "\improper Centcom bowman headset"
 	desc = "A headset especially for emergency response personnel. Protects ears from flashbangs. \nTo access the centcom channel, use :y."
-	flags = EARBANGPROTECT
 	icon_state = "cent_headset_alt"
 	item_state = "cent_headset_alt"
 	keyslot = null
 
+/obj/item/device/radio/headset/headset_cent/alt/Initialize(mapload)
+	..()
+	SET_SECONDARY_FLAG(src, BANG_PROTECT)
+
 /obj/item/device/radio/headset/ai
 	name = "\proper Integrated Subspace Transceiver "
 	keyslot2 = new /obj/item/device/encryptionkey/ai