Fix F-droid build: Added SubscriptionRebrandingFeatureToggleDummy (#6482)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/1201807753394693/task/1210911335127069?focus=true

### Description
Added SubscriptionRebrandingFeatureToggleDummy so F-droid builds are
fixed

### Steps to test this PR

- [ ] Build F-Droid apk CI check is green ✅ 

### No UI changes

Author: nalcalag

subscriptions/subscriptions-dummy-impl/src/main/java/com/duckduckgo/subscriptions/impl/SubscriptionRebrandingFeatureToggleDummy.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 DuckDuckGo
+ *
+ * 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.duckduckgo.subscriptions.impl
+
+import com.duckduckgo.di.scopes.AppScope
+import com.duckduckgo.subscriptions.api.SubscriptionRebrandingFeatureToggle
+import com.squareup.anvil.annotations.ContributesBinding
+import javax.inject.Inject
+
+@ContributesBinding(
+    scope = AppScope::class,
+    boundType = SubscriptionRebrandingFeatureToggle::class,
+)
+class SubscriptionRebrandingFeatureToggleDummy @Inject constructor() : SubscriptionRebrandingFeatureToggle {
+
+    override fun isSubscriptionRebrandingEnabled(): Boolean {
+        return false
+    }
+}