Issue #3454305: Plugin/Field/FieldType/PaymentMethod/generateSampleValue is static, but uses $this

Closes #3454305

Index Out of Bounds:

values[array_rand(values)]: This method will always generate a valid index within the bounds of the array. values[rand(0, count(values))]: This can potentially generate an index equal to count($values), which is out of bounds and will cause an error. Performance and Readability:

**values[array_rand(values)]: ** This method is more readable and clearly conveys the intent of selecting a random element from the array. values[rand(0, count(values))]: Even if corrected to values[rand(0, count(values) - 1)], it is less readable and more error-prone. Correct and Safe Usage: Preferred Method: values[array_rand(values)] This ensures that a valid index is always selected, preventing any potential index out-of-bounds errors.