Make default user agent string configurable

app/src/main/java/eu/kanade/tachiyomi/network/NetworkHelper.kt

@@ -60,4 +60,8 @@ class NetworkHelper(context: Context) {
             .addInterceptor(CloudflareInterceptor(context))
             .build()
     }
+
+    val defaultUserAgent by lazy {
+        preferences.defaultUserAgent().get()
+    }
 }

app/src/main/java/eu/kanade/tachiyomi/network/interceptor/CloudflareInterceptor.kt

@@ -9,7 +9,6 @@ import android.widget.Toast
 import androidx.core.content.ContextCompat
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.network.NetworkHelper
-import eu.kanade.tachiyomi.source.online.HttpSource
 import eu.kanade.tachiyomi.util.lang.launchUI
 import eu.kanade.tachiyomi.util.system.DeviceUtil
 import eu.kanade.tachiyomi.util.system.WebViewClientCompat
@@ -109,7 +108,7 @@ class CloudflareInterceptor(private val context: Context) : Interceptor {
 
             // Avoid sending empty User-Agent, Chromium WebView will reset to default if empty
             webview.settings.userAgentString = request.header("User-Agent")
-                ?: HttpSource.DEFAULT_USER_AGENT
+                ?: networkHelper.defaultUserAgent
 
             webview.webViewClient = object : WebViewClientCompat() {
                 override fun onPageFinished(view: WebView, url: String) {

app/src/main/java/eu/kanade/tachiyomi/network/interceptor/UserAgentInterceptor.kt

@@ -1,10 +1,14 @@
 package eu.kanade.tachiyomi.network.interceptor
 
-import eu.kanade.tachiyomi.source.online.HttpSource
+import eu.kanade.tachiyomi.network.NetworkHelper
 import okhttp3.Interceptor
 import okhttp3.Response
+import uy.kohesive.injekt.injectLazy
 
 class UserAgentInterceptor : Interceptor {
+
+    private val networkHelper: NetworkHelper by injectLazy()
+
     override fun intercept(chain: Interceptor.Chain): Response {
         val originalRequest = chain.request()
 
@@ -12,7 +16,7 @@ class UserAgentInterceptor : Interceptor {
             val newRequest = originalRequest
                 .newBuilder()
                 .removeHeader("User-Agent")
-                .addHeader("User-Agent", HttpSource.DEFAULT_USER_AGENT)
+                .addHeader("User-Agent", networkHelper.defaultUserAgent)
                 .build()
             chain.proceed(newRequest)
         } else {