You can override VS Code pretty settings by adding a .prettierrc file to the root of your project to override javascript double quote with a single quote.
NOTE: Prettier extension for VSCode is required to do this.
The below configuration will set .js extension files to use a single quote.
{
"singleQuote": false,
"overrides": [
{
"files": ["**/*.js"],
"options": {
"singleQuote": true
}
}
]
}