Add package manager to Angular app

Adding packageManager in angular.json

{``
    "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
    "version": 1,
    "newProjectRoot": "projects",
    "projects" {
        ...
    },
    "cli": {
        "packageManager": "npm" // either select yarn, npm, pnpm or cnpm
    }
}