[testnet] Align testnet system parachain runtimes using RelayTreasuryLocation and SystemParachains in the same way (#2023)

This PR addresses several issues:
- simplify referencing `RelayTreasuryLocation` without needing
additional `RelayTreasury` struct
- fix for referencing `SystemParachains` from parachain with `parents:
1` instead of `parents: 0`
- removed hard-coded constants and fix tests for `asset-hub-rococo`
which was merged to master after
https://github.com/paritytech/polkadot-sdk/pull/1726

---------

Co-authored-by: command-bot <>

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/xcm_config.rs

@@ -29,7 +29,7 @@ use crate::{
 };
 use frame_support::{
 	match_types, parameter_types,
-	traits::{ConstU32, Contains, Everything, Nothing},
+	traits::{ConstU32, Contains, Equals, Everything, Nothing},
 };
 use frame_system::EnsureRoot;
 use pallet_xcm::XcmPassthrough;
@@ -40,7 +40,7 @@ use parachains_common::{
 };
 use polkadot_parachain_primitives::primitives::Sibling;
 use polkadot_runtime_common::xcm_sender::ExponentialPrice;
-use rococo_runtime_constants::system_parachain::SystemParachains;
+use rococo_runtime_constants::system_parachain;
 use sp_core::Get;
 use sp_runtime::traits::AccountIdConversion;
 use xcm::latest::prelude::*;
@@ -67,6 +67,7 @@ parameter_types! {
 	pub const MaxInstructions: u32 = 100;
 	pub const MaxAssetsIntoHolding: u32 = 64;
 	pub TreasuryAccount: Option<AccountId> = Some(TREASURY_PALLET_ID.into_account_truncating());
+	pub RelayTreasuryLocation: MultiLocation = (Parent, PalletInstance(rococo_runtime_constants::TREASURY_PALLET_ID)).into();
 }
 
 /// Adapter for resolving `NetworkId` based on `pub storage Flavor: RuntimeFlavor`.
@@ -222,8 +223,12 @@ pub type Barrier = TrailingSetTopicAsId<
 					// If the message is one that immediately attempts to pay for execution, then
 					// allow it.
 					AllowTopLevelPaidExecutionFrom<Everything>,
-					// Parent and its pluralities (i.e. governance bodies) get free execution.
-					AllowExplicitUnpaidExecutionFrom<ParentOrParentsPlurality>,
+					// Parent, its pluralities (i.e. governance bodies) and relay treasury pallet
+					// get free execution.
+					AllowExplicitUnpaidExecutionFrom<(
+						ParentOrParentsPlurality,
+						Equals<RelayTreasuryLocation>,
+					)>,
 					// Subscriptions for version tracking are OK.
 					AllowSubscriptionsFrom<ParentOrSiblings>,
 				),
@@ -234,22 +239,25 @@ pub type Barrier = TrailingSetTopicAsId<
 	>,
 >;
 
-parameter_types! {
-	pub RelayTreasuryLocation: MultiLocation = (Parent, PalletInstance(rococo_runtime_constants::TREASURY_PALLET_ID)).into();
-}
-
-pub struct RelayTreasury;
-impl Contains<MultiLocation> for RelayTreasury {
-	fn contains(location: &MultiLocation) -> bool {
-		let relay_treasury_location = RelayTreasuryLocation::get();
-		*location == relay_treasury_location
-	}
+match_types! {
+	pub type SystemParachains: impl Contains<MultiLocation> = {
+		MultiLocation {
+			parents: 1,
+			interior: X1(Parachain(
+				system_parachain::ASSET_HUB_ID |
+				system_parachain::BRIDGE_HUB_ID |
+				system_parachain::CONTRACTS_ID |
+				system_parachain::ENCOINTER_ID
+			)),
+		}
+	};
 }
 
 /// Locations that will not be charged fees in the executor,
 /// either execution or delivery.
 /// We only waive fees for system functions, which these locations represent.
-pub type WaivedLocations = (RelayOrOtherSystemParachains<SystemParachains, Runtime>, RelayTreasury);
+pub type WaivedLocations =
+	(RelayOrOtherSystemParachains<SystemParachains, Runtime>, Equals<RelayTreasuryLocation>);
 
 /// Cases where a remote origin is accepted as trusted Teleporter for a given asset:
 /// - NativeToken with the parent Relay Chain and sibling parachains.