bool-param-default should ignore type declaration when function has meet requirements

[michaelw85]

I want to report a bug.

SonarTS version: 1.9.0

Node.js version: v10.15.1

TypeScript version: 3.4.5

SonarQube version: N/A

SonarLint version and used IDE: No, vscode

TSLint version: 5.16.0

Rule key:
bool-param-default
Provide a default value for 'devMode' so that the logic of the function is more evident when this parameter is missing. Consider defining another function if providing default value is not possible.

Reproducer

// Rules fires due to devMode?: boolean
const configure: (config: FrameworkConfiguration, devMode?: boolean) => FrameworkConfiguration = (
    config: FrameworkConfiguration,
    devMode: boolean = false
): FrameworkConfiguration => // function logic

Expected behavior
Rule should not throw error for type declaration if function sets a default value.