refactor: overwrite ArbitrageMinGasPrice config from .005 to 0.1 (#7368)

Closes: #XXX

## What is the purpose of the change

To address the failing arbitrage spam taking up block space, we will increase [arbitrage-min-gas-fee](https://github.com/osmosis-labs/osmosis/blob/3aaf5d117f96df0092b0375d0c8de0a12850d092/cmd/osmosisd/cmd/root.go#L540) to be near the order of magnitude of 0.1 OSMO.

CL Swap is around 600K gas wanted and 340K gas used. Let's assume a middle ground of 450K and aim to have the arb pay approximately 0.05 OSMO.
```
0.045 = 450_000 * 0.1 / 10**6
```
 As a result, 0.1 is an appropriate choice.

## Testing and Verifying

Tested the following vectors:
- new config
- does no overwrite other values
- old value is "0.005" -> overwritten
- old value is ".005" -> overwritten
- old value is something else -> does not change

## Documentation and Release Note

  - [ ] Does this pull request introduce a new feature or user-facing behavior changes?
  - [ ] Changelog entry added to `Unreleased` section of `CHANGELOG.md`?

Where is the change documented?
  - [ ] Specification (`x/{module}/README.md`)
  - [ ] Osmosis documentation site
  - [ ] Code comments?
  - [ ] N/A

(cherry picked from commit af1ed8c)

CHANGELOG.md

@@ -46,6 +46,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * [#7346](https://github.com/osmosis-labs/osmosis/pull/7346) Prevent heavy gRPC load from app hashing nodes
 
+### Config
+
+* [#7368](https://github.com/osmosis-labs/osmosis/pull/7368) Overwrite ArbitrageMinGasPriceconfig from .005 to 0.1.
+
 ## v22.0.0
 
 ### Fee Market Parameter Updates

cmd/osmosisd/cmd/root.go

@@ -94,6 +94,11 @@ type DenomUnitMap struct {
 }
 
 const (
+	mempoolConfigName            = "osmosis-mempool"
+	arbitrageMinGasFeeConfigName = "arbitrage-min-gas-fee"
+	oldArbitrageMinGasFeeValue   = ".005"
+	newArbitrageMinGasFeeValue   = "0.1"
+
 	consensusConfigName     = "consensus"
 	timeoutCommitConfigName = "timeout_commit"
 )
@@ -477,6 +482,79 @@ func overwriteConfigTomlValues(serverCtx *server.Context) error {
 	return nil
 }
 
+// overwrites app.toml values. Returns error if app.toml does not exist
+//
+// Currently, overwrites arbitrage-min-gas-fee value in app.toml if it is set to 0.005. Similarly,
+// overwrites the given viper config value.
+// Silently handles and skips any error/panic due to write permission issues.
+// No-op otherwise.
+func overwriteAppTomlValues(serverCtx *server.Context) error {
+	// Get paths to config.toml and config parent directory
+	rootDir := serverCtx.Viper.GetString(tmcli.HomeFlag)
+
+	configParentDirPath := filepath.Join(rootDir, "config")
+	configFilePath := filepath.Join(configParentDirPath, "app.toml")
+
+	fileInfo, err := os.Stat(configFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to read in %s: %w", configFilePath, err)
+	} else {
+		// app.toml exists
+
+		// Get setting
+		currentArbitrageMinGasFeeValue := serverCtx.Viper.Get(mempoolConfigName + "." + arbitrageMinGasFeeConfigName)
+
+		// .x format at 0.x format are both valid.
+		if currentArbitrageMinGasFeeValue == oldArbitrageMinGasFeeValue || currentArbitrageMinGasFeeValue == "0"+oldArbitrageMinGasFeeValue {
+			// Set new value in viper
+			serverCtx.Viper.Set(mempoolConfigName+"."+arbitrageMinGasFeeConfigName, newArbitrageMinGasFeeValue)
+
+			defer func() {
+				if err := recover(); err != nil {
+					fmt.Printf("failed to write to %s: %s\n", configFilePath, err)
+				}
+			}()
+
+			// Check if the file is writable
+			if fileInfo.Mode()&os.FileMode(0200) != 0 {
+				// Read the entire content of the file
+				content, err := os.ReadFile(configFilePath)
+				if err != nil {
+					return err
+				}
+
+				// Convert the content to a string
+				fileContent := string(content)
+
+				// Find the index of the search line
+				index := strings.Index(fileContent, arbitrageMinGasFeeConfigName)
+				if index == -1 {
+					return fmt.Errorf("search line not found in the file")
+				}
+
+				// Find the opening and closing quotes
+				openQuoteIndex := strings.Index(fileContent[index:], "\"")
+				openQuoteIndex += index
+
+				closingQuoteIndex := strings.Index(fileContent[openQuoteIndex+1:], "\"")
+				closingQuoteIndex += openQuoteIndex + 1
+
+				// Replace the old value with the new value
+				newFileContent := fileContent[:openQuoteIndex+1] + newArbitrageMinGasFeeValue + fileContent[closingQuoteIndex:]
+
+				// Write the modified content back to the file
+				err = os.WriteFile(configFilePath, []byte(newFileContent), 0644)
+				if err != nil {
+					return err
+				}
+			} else {
+				fmt.Println("app.toml is not writable. Cannot apply update. Please consder manually changing arbitrage-min-gas-fee to " + newArbitrageMinGasFeeValue)
+			}
+		}
+	}
+	return nil
+}
+
 func getHomeEnvironment() string {
 	envPath := filepath.Join(osmosis.DefaultNodeHome, ".env")
 
@@ -519,7 +597,7 @@ func initAppConfig() (string, interface{}) {
 	// 128MB IAVL cache
 	srvCfg.IAVLCacheSize = 781250
 
-	memCfg := OsmosisMempoolConfig{ArbitrageMinGasPrice: "0.01"}
+	memCfg := OsmosisMempoolConfig{ArbitrageMinGasPrice: "0.1"}
 
 	sqsConfig := sqs.DefaultConfig
 
@@ -536,8 +614,8 @@ func initAppConfig() (string, interface{}) {
 max-gas-wanted-per-tx = "25000000"
 
 # This is the minimum gas fee any arbitrage tx should have, denominated in uosmo per gas
-# Default value of ".005" then means that a tx with 1 million gas costs (.005 uosmo/gas) * 1_000_000 gas = .005 osmo
-arbitrage-min-gas-fee = ".005"
+# Default value of ".1" then means that a tx with 1 million gas costs (.1 uosmo/gas) * 1_000_000 gas = .1 osmo
+arbitrage-min-gas-fee = ".1"
 
 # This is the minimum gas fee any tx with high gas demand should have, denominated in uosmo per gas
 # Default value of ".0025" then means that a tx with 1 million gas costs (.0025 uosmo/gas) * 1_000_000 gas = .0025 osmo
@@ -619,6 +697,12 @@ func initRootCmd(rootCmd *cobra.Command, encodingConfig params.EncodingConfig) {
 					return err
 				}
 
+				// overwrite app.toml values
+				err = overwriteAppTomlValues(serverCtx)
+				if err != nil {
+					return err
+				}
+
 				return startRunE(cmd, args)
 			}