Add ReferrerService

fake-store/src/main/AndroidManifest.xml

@@ -36,12 +36,21 @@
             </intent-filter>
         </service>
 
+        <service
+            android:name="com.google.android.finsky.externalreferrer.GetInstallReferrerService"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="com.google.android.finsky.BIND_GET_INSTALL_REFERRER_SERVICE" />
+            </intent-filter>
+        </service>
+
         <activity
             android:name="org.microg.vending.ui.MainActivity"
             android:theme="@style/Theme.Dialog.NoActionBar"
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
+
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.INFO" />
             </intent-filter>

fake-store/src/main/aidl/com/google/android/finsky/externalreferrer/IGetInstallReferrerService.aidl

@@ -0,0 +1,10 @@
+/*
+ * SPDX-FileCopyrightText: 2023 microG Project Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.google.android.finsky.externalreferrer;
+
+interface IGetInstallReferrerService {
+    Bundle getInstallReferrer(in Bundle request);
+}

fake-store/src/main/java/com/google/android/finsky/externalreferrer/GetInstallReferrerService.java

@@ -0,0 +1,38 @@
+/*
+ * SPDX-FileCopyrightText: 2023 microG Project Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.google.android.finsky.externalreferrer;
+
+import android.app.Service;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.os.RemoteException;
+
+public class GetInstallReferrerService extends Service {
+    private static final String TAG = "FakeReferrerService";
+
+    private final IGetInstallReferrerService.Stub service = new IGetInstallReferrerService.Stub() {
+        // https://developer.android.com/google/play/installreferrer/igetinstallreferrerservice
+        @Override
+        public Bundle getInstallReferrer(Bundle request) throws RemoteException {
+            String packageName = request.getString("package_name");
+            Bundle result = new Bundle();
+            result.putString("install_referrer", "https://play.google.com/store/apps/details?utm_source=google-play&utm_medium=organic&id="+packageName);
+            result.putLong("referrer_click_timestamp_seconds", 0);
+            result.putLong("referrer_click_timestamp_server_seconds", 0);
+            result.putLong("install_begin_timestamp_seconds", 0);
+            result.putLong("install_begin_timestamp_server_seconds", 0);
+            result.putString("install_version", null);
+            result.putBoolean("google_play_instant", false);
+            return result;
+        }
+    };
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return service.asBinder();
+    }
+}