set main shell builder once

app/src/main/AndroidManifest.xml

@@ -14,6 +14,7 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.KsuWebUI"
         android:networkSecurityConfig="@xml/network_security_config"
+        android:name=".App"
         tools:targetApi="31" >
         <activity android:name=".MainActivity"
             android:exported="true">

app/src/main/java/io/github/a13e300/ksuwebui/App.kt

@@ -0,0 +1,11 @@
+package io.github.a13e300.ksuwebui
+
+import android.app.Application
+import com.topjohnwu.superuser.Shell
+
+class App : Application() {
+    override fun onCreate() {
+        super.onCreate()
+        Shell.setDefaultBuilder(Shell.Builder.create().setFlags(Shell.FLAG_MOUNT_MASTER))
+    }
+}

app/src/main/java/io/github/a13e300/ksuwebui/MainActivity.kt

@@ -177,7 +177,6 @@ class MainActivity : AppCompatActivity() {
                 }
 
             }
-            Shell.setDefaultBuilder(Shell.Builder.create().setFlags(Shell.FLAG_MOUNT_MASTER))
             runOnUiThread {
                 RootService.bind(Intent(this, FileSystemService::class.java), connection!!)
             }