add _ prefix to the internal interface

Author: Feiyang1

packages-exp/installations-exp/src/functions/config.ts

@@ -24,7 +24,7 @@ import {
   ComponentContainer
 } from '@firebase/component';
 import { getId, getToken } from '../api/index';
-import { FirebaseInstallationsInternal } from '@firebase/installations-types-exp';
+import { _FirebaseInstallationsInternal } from '@firebase/installations-types-exp';
 import { FirebaseInstallationsImpl } from '../interfaces/installation-impl';
 import { extractAppConfig } from '../helpers/extract-app-config';
 
@@ -55,7 +55,7 @@ const internalFactory: InstanceFactory<'installations-exp-internal'> = (
   // Internal FIS instance relies on public FIS instance.
   const installations = _getProvider(app, INSTALLATIONS_NAME).getImmediate();
 
-  const installationsInternal: FirebaseInstallationsInternal = {
+  const installationsInternal: _FirebaseInstallationsInternal = {
     getId: () => getId(installations),
     getToken: (forceRefresh?: boolean) => getToken(installations, forceRefresh)
   };

packages-exp/installations-types-exp/index.d.ts

@@ -15,8 +15,6 @@
  * limitations under the License.
  */
 
-import { FirebaseInstallationsImpl } from '../installations-exp/src/interfaces/installation-impl';
-
 /**
  * @public
  */
@@ -27,7 +25,7 @@ export interface FirebaseInstallations {}
  * 
  * @internal
  */
-export interface FirebaseInstallationsInternal {
+export interface _FirebaseInstallationsInternal {
   /**
    * Creates a Firebase Installation if there isn't one for the app and
    * returns the Installation ID.
@@ -43,6 +41,6 @@ export interface FirebaseInstallationsInternal {
 declare module '@firebase/component' {
   interface NameServiceMapping {
     'installations-exp': FirebaseInstallations;
-    'installations-exp-internal': FirebaseInstallationsInternal;
+    'installations-exp-internal': _FirebaseInstallationsInternal;
   }
 }