Revert "Fix serialization of `transaction_paymentInfo`" (#4166)

* Revert "Fix serialization of `transaction_paymentInfo` (#4146)"

This reverts commit a15b33a0.

* Revert chain-spec too.

* Bring back camelCase and test.

client/chain-spec/Cargo.toml

@@ -10,6 +10,6 @@ impl-trait-for-tuples = "0.1.3"
 network = { package = "substrate-network", path = "../network" }
 primitives = { package = "substrate-primitives", path = "../../primitives/core" }
 serde = { version = "1.0.101", features = ["derive"] }
-serde_json = { version = "1.0.41", features = [ "arbitrary_precision" ] }
+serde_json = "1.0.41"
 sr-primitives = { path = "../../primitives/sr-primitives" }
 tel = { package = "substrate-telemetry", path = "../telemetry" }

client/rpc/Cargo.toml

@@ -16,7 +16,7 @@ log = "0.4.8"
 primitives = { package = "substrate-primitives", path = "../../primitives/core" }
 rpc = { package = "jsonrpc-core", version = "14.0.3" }
 runtime_version = { package = "sr-version", path = "../../primitives/sr-version" }
-serde_json = { version = "1.0.41", features = ["arbitrary_precision"] }
+serde_json = "1.0.41"
 session = { package = "substrate-session", path = "../../primitives/session" }
 sr-primitives = { path = "../../primitives/sr-primitives" }
 rpc-primitives = { package = "substrate-rpc-primitives", path = "../../primitives/rpc" }

palette/transaction-payment/rpc/runtime-api/Cargo.toml

@@ -12,7 +12,7 @@ rstd = { package = "sr-std", path = "../../../../primitives/sr-std", default-fea
 sr-primitives = { path = "../../../../primitives/sr-primitives", default-features = false }
 
 [dev-dependencies]
-serde_json = { version = "1.0.41", features = ["arbitrary_precision"] }
+serde_json = "1.0.41"
 
 [features]
 default = ["std"]

palette/transaction-payment/rpc/runtime-api/src/lib.rs

@@ -52,11 +52,11 @@ mod tests {
 	use super::*;
 
 	#[test]
-	fn should_serialize_properly_with_u128() {
+	fn should_serialize_properly_with_u64() {
 		let info = RuntimeDispatchInfo {
 			weight: 5,
 			class: DispatchClass::Normal,
-			partial_fee: 1_000_000_u128,
+			partial_fee: 1_000_000_u64,
 		};
 
 		assert_eq!(