Fix missing GBP conversion rate in currency_conversion.json

[scott-clare1]

Issue Description

The currencyservice is failing to convert currencies to GBP, causing errors and switching back to the original currency.

Root Cause

In the currency_conversion.json file, the GBP currency rate is set to an empty string:

"GBP": "",

This causes the conversion calculation to return zero when attempting to convert to GBP, which triggers the error handling code in the convert function in server.js:

// Check if the result is zero
if (result.units === 0 && result.nanos === 0) {
  logger.error(`Currency conversion resulted in zero amount, switching back to original currency`);
  notifySlack();
  
  // Switch back to the original currency
  result.currency_code = request.from.currency_code;
  result.units = request.from.units;
  result.nanos = request.from.nanos;
  
  callback(null, result);
  return;
}

Proposed Fix

Update the currency_conversion.json file by adding the correct conversion rate for GBP. Based on the other conversion rates in the file, the GBP should have a valid numeric value.

{
  "EUR": "1.0",
  "USD": "1.1305",
  "JPY": "126.40",
  "BGN": "1.9558",
  "CZK": "25.592",
  "DKK": "7.4609",
-  "GBP": "",
+  "GBP": "0.8508",
  "HUF": "315.51",
  "PLN": "4.2996",
  "RON": "4.7463",
  "SEK": "10.5375",
  "CHF": "1.1360",
  "ISK": "136.80",
  "NOK": "9.8040",
  "HRK": "7.4210",
  "RUB": "74.4208",
  "TRY": "6.1247",
  "AUD": "1.6072",
  "BRL": "4.2682",
  "CAD": "1.5128",
  "CNY": "7.5857",
  "HKD": "8.8743",
  "IDR": "15999.40",
  "ILS": "4.0875",
  "INR": "79.4320",
  "KRW": "1275.05",
  "MXN": "21.7999",
  "MYR": "4.6289",
  "NZD": "1.6679",
  "PHP": "59.083",
  "SGD": "1.5349",
  "THB": "36.012",
  "ZAR": "16.0583"
}

The value 0.8508 is a realistic EUR to GBP conversion rate (based on historical data from around the time the other rates were defined). This will fix the GBP currency conversion issues.

Impact

• This fix will allow users to properly convert prices to GBP currency
• It will eliminate the error logs and Slack notifications related to GBP conversions
• The e-commerce platform will provide a better user experience for customers wanting to see prices in GBP