Contracts: Remove ED from base deposit (#3536)

- Update internal logic so that the storage_base_deposit does not
include ED
- add v16 migration to update ContractInfo struct with this change

Before:
<img width="820" alt="Screenshot 2024-03-21 at 11 23 29"
src="https://github.com/paritytech/polkadot-sdk/assets/521091/a0a8df0d-e743-42c5-9e16-cf2ec1aa949c">

After:
![Screenshot 2024-03-21 at 11 23
42](https://github.com/paritytech/polkadot-sdk/assets/521091/593235b0-b866-4915-b653-2071d793228b)

---------

Co-authored-by: Cyrill Leutwiler <cyrill@parity.io>
Co-authored-by: command-bot <>

substrate/frame/contracts/src/benchmarking/mod.rs

@@ -32,7 +32,7 @@ use self::{
 use crate::{
 	exec::Key,
 	migration::{
-		codegen::LATEST_MIGRATION_VERSION, v09, v10, v11, v12, v13, v14, v15, MigrationStep,
+		codegen::LATEST_MIGRATION_VERSION, v09, v10, v11, v12, v13, v14, v15, v16, MigrationStep,
 	},
 	Pallet as Contracts, *,
 };
@@ -331,6 +331,26 @@ mod benchmarks {
 		Ok(())
 	}
 
+	// This benchmarks the v16 migration step (Remove ED from base_deposit).
+	#[benchmark(pov_mode = Measured)]
+	fn v16_migration_step() -> Result<(), BenchmarkError> {
+		let contract =
+			<Contract<T>>::with_caller(whitelisted_caller(), WasmModule::dummy(), vec![])?;
+
+		let info = contract.info()?;
+		let base_deposit = v16::store_old_contract_info::<T>(contract.account_id.clone(), &info);
+		let mut m = v16::Migration::<T>::default();
+
+		#[block]
+		{
+			m.step(&mut WeightMeter::new());
+		}
+		let ed = Pallet::<T>::min_balance();
+		let info = v16::ContractInfoOf::<T>::get(&contract.account_id).unwrap();
+		assert_eq!(info.storage_base_deposit, base_deposit - ed);
+		Ok(())
+	}
+
 	// This benchmarks the weight of executing Migration::migrate to execute a noop migration.
 	#[benchmark(pov_mode = Measured)]
 	fn migration_noop() {