evm: fix AddLog unmarshaling tx (#192)

* fix `AddLog` unmarshaling tx

Closes #187

* use cosmos tx in AddLog unit test

* Apply suggestions from code review

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

app/app.go

@@ -229,13 +229,14 @@ func NewEthermintApp(
 	appCodec := encodingConfig.Marshaler
 	cdc := encodingConfig.Amino
 	interfaceRegistry := encodingConfig.InterfaceRegistry
+	txDecoder := encodingConfig.TxConfig.TxDecoder()
 
 	// NOTE we use custom transaction decoder that supports the sdk.Tx interface instead of sdk.StdTx
 	bApp := baseapp.NewBaseApp(
 		appName,
 		logger,
 		db,
-		encodingConfig.TxConfig.TxDecoder(),
+		txDecoder,
 		baseAppOptions...,
 	)
 	bApp.SetCommitMultiStoreTracer(traceStore)
@@ -311,7 +312,7 @@ func NewEthermintApp(
 
 	// Create Ethermint keepers
 	app.EvmKeeper = evmkeeper.NewKeeper(
-		appCodec, keys[evmtypes.StoreKey], tkeys[evmtypes.TransientKey], app.GetSubspace(evmtypes.ModuleName),
+		appCodec, txDecoder, keys[evmtypes.StoreKey], tkeys[evmtypes.TransientKey], app.GetSubspace(evmtypes.ModuleName),
 		app.AccountKeeper, app.BankKeeper, app.StakingKeeper,
 	)