fix: Add userFeeLevel as dappSuggested initially when txParams contains gas values for legacy transactions (#5821)

## Explanation

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This PR aims to add `userFeeLevel` as `dappSuggested` initially when
`txParams` contains gas values also for `legacy` transactions.

## References

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* Issue found while implementing gas modal:
MetaMask/metamask-mobile#15234

## Changelog

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## Checklist

- [X] I've updated the test suite for new or updated code as appropriate
- [X] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [X] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [X] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

Author: OGPoyraz

packages/transaction-controller/CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fix `userFeeLevel` as `dappSuggested` initially when dApp suggested gas values for legacy transactions ([#5821](https://github.com/MetaMask/core/pull/5821))
 - Fix `addTransaction` function to correctly identify a transaction as a `simpleSend` type when the recipient is a smart account ([#5822](https://github.com/MetaMask/core/pull/5822))
 
 ## [56.1.0]

packages/transaction-controller/src/TransactionController.ts

@@ -118,11 +118,11 @@ import type {
   GasFeeEstimateLevel as GasFeeEstimateLevelType,
 } from './types';
 import {
+  GasFeeEstimateLevel,
   TransactionEnvelopeType,
   TransactionType,
   TransactionStatus,
   SimulationErrorCode,
-  GasFeeEstimateLevel,
 } from './types';
 import {
   addTransactionBatch,

packages/transaction-controller/src/utils/gas-fees.test.ts

@@ -487,14 +487,6 @@ describe('gas-fees', () => {
     });
 
     describe('sets userFeeLevel', () => {
-      it('to undefined if not eip1559', async () => {
-        updateGasFeeRequest.eip1559 = false;
-
-        await updateGasFees(updateGasFeeRequest);
-
-        expect(updateGasFeeRequest.txMeta.userFeeLevel).toBeUndefined();
-      });
-
       it('to saved userFeeLevel if saved gas fees defined', async () => {
         updateGasFeeRequest.txMeta.type = TransactionType.simpleSend;
         updateGasFeeRequest.getSavedGasFees.mockReturnValueOnce({

packages/transaction-controller/src/utils/gas-fees.ts

@@ -283,12 +283,7 @@ function getGasPrice(request: GetGasFeeRequest): string | undefined {
  * @returns The user fee level.
  */
 function getUserFeeLevel(request: GetGasFeeRequest): UserFeeLevel | undefined {
-  const { eip1559, initialParams, savedGasFees, suggestedGasFees, txMeta } =
-    request;
-
-  if (!eip1559) {
-    return undefined;
-  }
+  const { initialParams, savedGasFees, suggestedGasFees, txMeta } = request;
 
   if (savedGasFees) {
     return UserFeeLevel.CUSTOM;