Support talkback for toggle buttons in port forwarding setting

Port number is 8080 for instance:
Before: On/Off. Switch. Double tap to toggle
After: On/Off. 8080 Switch. Double tap to toggle

Bug: 376796655
Test: Run VmTerminalApp with enabling talkback
Change-Id: Ia3ef7021c82c77dbfe10b271e16e1822f6326df0
diff --git a/android/TerminalApp/java/com/android/virtualization/terminal/SettingsPortForwardingAdapter.kt b/android/TerminalApp/java/com/android/virtualization/terminal/SettingsPortForwardingAdapter.kt
index 436ea21..c3501d4 100644
--- a/android/TerminalApp/java/com/android/virtualization/terminal/SettingsPortForwardingAdapter.kt
+++ b/android/TerminalApp/java/com/android/virtualization/terminal/SettingsPortForwardingAdapter.kt
@@ -97,6 +97,7 @@
 
     override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
         viewHolder.port.text = mItems[position].port.toString()
+        viewHolder.enabledSwitch.contentDescription = viewHolder.port.text
         viewHolder.enabledSwitch.isChecked = mItems[position].enabled
         viewHolder.enabledSwitch.setOnCheckedChangeListener { _, isChecked ->
             val sharedPref: SharedPreferences = context.getSharedPreferences(