Add SpaEnvironmentFactory

    package="com.android.settingslib.spa.gallery">

    <application

        android:name=".GalleryApplication"

        android:icon="@mipmap/ic_launcher"

        android:label="@string/app_label"

        android:supportsRtl="true"

        android:enableOnBackInvokedCallback="true">

        <activity

            android:name=".MainActivity"

            android:name=".GalleryMainActivity"

            android:exported="true">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

/*

 * Copyright (C) 2022 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.android.settingslib.spa.gallery

import android.app.Application

import com.android.settingslib.spa.framework.common.SpaEnvironmentFactory

class GalleryApplication : Application() {

    override fun onCreate() {

        super.onCreate()

        SpaEnvironmentFactory.instance = GallerySpaEnvironment

    }

}

 No newline at end of file

import com.android.settingslib.spa.framework.DebugActivity

class GalleryDebugActivity : DebugActivity(GallerySpaEnvironment)

class GalleryDebugActivity : DebugActivity()

import com.android.settingslib.spa.framework.EntryProvider

class GalleryEntryProvider : EntryProvider(GallerySpaEnvironment)

class GalleryEntryProvider : EntryProvider()

import com.android.settingslib.spa.framework.BrowseActivity

class MainActivity : BrowseActivity(GallerySpaEnvironment)

class GalleryMainActivity : BrowseActivity()