Merge branch 'jamesdaniels_ssr_autoconfig' of https://github.com/firebase/firebase-js-sdk into ch-ssr-autoconfig

Author: hsubox76

common/api-review/firestore.api.md

@@ -233,6 +233,9 @@ export function getFirestore(): Firestore;
 // @public
 export function getFirestore(app: FirebaseApp): Firestore;
 
+// @public
+export function getFirestore(): Firestore;
+
 // @public
 export function increment(n: number): FieldValue;