Add optional workaround for bug with non-existing local user ubuntu to devcontainer.json

Some IDEs (looking at you, CLion) throw an error when building the container and can't find a local user named ubuntu in /etc/passwd. Disable updating the user ID in those cases to fix the build issue. A manual UID change using Docker run arguments might be needed in that case when your local user has a UID != 1000.

Author: dariusarnold

.devcontainer.json

@@ -34,4 +34,8 @@
 		}
 	},
 	"remoteUser": "ubuntu"
+	// This might be needed when you do not have a local user called ubuntu but your dev container
+	// implementation tries to find it in the local /etc/passwd and fails to build your container.
+	// The default is true.
+	//,"updateRemoteUserUID": false
 }