refactor: move USB device observation out of the init method

Author: superus8r

app/src/main/java/org/kabiri/android/usbterminal/MainActivity.kt

@@ -16,7 +16,9 @@ import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
 import org.kabiri.android.usbterminal.util.scrollToLastLine
@@ -36,6 +38,7 @@ class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        viewModel.startObservingUsbDevice()
         setContentView(R.layout.activity_main)
 
         // avoid system navbar or soft keyboard overlapping the content.

app/src/main/java/org/kabiri/android/usbterminal/viewmodel/MainActivityViewModel.kt

@@ -49,7 +49,7 @@ internal class MainActivityViewModel
 
     val output2 = SnapshotStateList<OutputText>()
 
-    init {
+    internal fun startObservingUsbDevice() {
         // Subscribe to USB device changes.
         viewModelScope.launch {
             usbUseCase.usbDevice.collect { device ->