Add option to opt out of Analytics and Crashlytics (#1237)

app/src/standard/AndroidManifest.xml

@@ -20,6 +20,15 @@
         tools:node="remove" />
 
     <application>
+        <!-- Disable for manual opt-in -->
+        <meta-data
+            android:name="firebase_analytics_collection_enabled"
+            android:value="false" />
+
+        <meta-data
+            android:name="firebase_crashlytics_collection_enabled"
+            android:value="false" />
+
         <!-- Disable unnecessary stuff from Firebase -->
         <meta-data
             android:name="google_analytics_adid_collection_enabled"

app/src/standard/java/mihon/core/firebase/Firebase.kt

@@ -0,0 +1,20 @@
+package mihon.core.firebase
+
+import android.content.Context
+import com.google.firebase.analytics.FirebaseAnalytics
+import com.google.firebase.crashlytics.FirebaseCrashlytics
+import eu.kanade.tachiyomi.core.security.PrivacyPreferences
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+
+object Firebase {
+    fun setup(context: Context, preference: PrivacyPreferences, scope: CoroutineScope) {
+        preference.analytics().changes().onEach { enabled ->
+            FirebaseAnalytics.getInstance(context).setAnalyticsCollectionEnabled(enabled)
+        }.launchIn(scope)
+        preference.crashlytics().changes().onEach { enabled ->
+            FirebaseCrashlytics.getInstance().setCrashlyticsCollectionEnabled(enabled)
+        }.launchIn(scope)
+    }
+}