Update docs to reference Installations SDK.

Author: danasilver

firebase-config/src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java

@@ -66,10 +66,10 @@ public class FirebaseRemoteConfig {
    * <p>{@link FirebaseRemoteConfig} uses the default {@link FirebaseApp}, so if no {@link
    * FirebaseApp} has been initialized yet, this method throws an {@link IllegalStateException}.
    *
-   * <p>To identify the current app instance, the fetch request creates a Firebase Instance ID
-   * token, which periodically sends data to the Firebase backend. To stop the periodic sync, call
-   * {@link com.google.firebase.iid.FirebaseInstanceId#deleteInstanceId}. To create a new token and
-   * resume the periodic sync, call {@code fetchConfig} again.
+   * <p>To identify the current app instance, the fetch request creates a Firebase Installations ID,
+   * which periodically sends data to the Firebase backend. To stop the periodic sync, call
+   * {@link com.google.firebase.installations.FirebaseInstallations#delete}. To create a new token
+   * and resume the periodic sync, call {@code fetch} again.
    *
    * @return A singleton instance of {@link FirebaseRemoteConfig} for the default {@link
    *     FirebaseApp}.
@@ -303,10 +303,10 @@ public Task<Boolean> activate() {
    * FirebaseRemoteConfigSettings.Builder#setMinimumFetchIntervalInSeconds(long)}; the static
    * default is 12 hours.
    *
-   * <p>To identify the current app instance, the fetch request creates a Firebase Instance ID
-   * token, which periodically sends data to the Firebase backend. To stop the periodic sync, call
-   * {@link com.google.firebase.iid.FirebaseInstanceId#deleteInstanceId}. To create a new token and
-   * resume the periodic sync, call {@code fetchConfig} again.
+   * <p>To identify the current app instance, the fetch request creates a Firebase Instance ID,
+   * which periodically sends data to the Firebase backend. To stop the periodic sync, call
+   * {@link com.google.firebase.installations.FirebaseInstallations#delete}. To create a new token
+   * and resume the periodic sync, call {@code fetch} again.
    *
    * @return {@link Task} representing the {@code fetch} call.
    */
@@ -326,10 +326,10 @@ public Task<Void> fetch() {
    * <p>Depending on the time elapsed since the last fetch from the Firebase Remote Config backend,
    * configs are either served from local storage, or fetched from the backend.
    *
-   * <p>To identify the current app instance, the fetch request creates a Firebase Instance ID
-   * token, which periodically sends data to the Firebase backend. To stop the periodic sync, call
-   * {@link com.google.firebase.iid.FirebaseInstanceId#deleteInstanceId}. To create a new token and
-   * resume the periodic sync, call {@code fetchConfig} again.
+   * <p>To identify the current app instance, the fetch request creates a Firebase Instance ID,
+   * which periodically sends data to the Firebase backend. To stop the periodic sync, call
+   * {@link com.google.firebase.installations.FirebaseInstallations#delete}. To create a new token
+   * and resume the periodic sync, call {@code fetch} again.
    *
    * @param minimumFetchIntervalInSeconds If configs in the local storage were fetched more than
    *     this many seconds ago, configs are served from the backend instead of local storage.