Improve WebView spoofing (#3678)

- Spoof `Sec-CH-UA` client hints to match the user agent
- Fix `X-Requested-With` spoofing leaking to unrelated callers
- Update default user agent to Chrome 149

app/src/main/java/eu/kanade/tachiyomi/App.kt

@@ -8,7 +8,6 @@ import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
 import android.os.Build
-import android.os.Looper
 import android.webkit.WebView
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.DefaultLifecycleObserver
@@ -231,7 +230,7 @@ class App : Application(), DefaultLifecycleObserver, SingletonImageLoader.Factor
     override fun getPackageName(): String {
         try {
             // Override the value passed as X-Requested-With in WebView requests
-            val stackTrace = Looper.getMainLooper().thread.stackTrace
+            val stackTrace = Thread.currentThread().stackTrace
             val isChromiumCall = stackTrace.any { trace ->
                 trace.className.lowercase() in setOf("org.chromium.base.buildinfo", "org.chromium.base.apkinfo") &&
                     trace.methodName.lowercase() in setOf("getall", "getpackagename", "<init>")