Add internal setting to copy service password.

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/internal/InternalSettingsFragment.kt

@@ -245,6 +245,14 @@ class InternalSettingsFragment : DSLSettingsFragment(R.string.preferences__inter
         )
       }
 
+      clickPref(
+        title = DSLSettingsText.from("Copy service password"),
+        summary = DSLSettingsText.from("Copy the password used to authenticate with the service."),
+        onClick = {
+          onCopyServicePasswordClicked()
+        }
+      )
+
       clickPref(
         title = DSLSettingsText.from("Unregister"),
         summary = DSLSettingsText.from("This will unregister your account without deleting it."),
@@ -1147,6 +1155,24 @@ class InternalSettingsFragment : DSLSettingsFragment(R.string.preferences__inter
       .show()
   }
 
+  private fun onCopyServicePasswordClicked() {
+    val servicePassword = SignalStore.account.servicePassword
+    if (servicePassword == null) {
+      Toast.makeText(requireContext(), "No service password set!", Toast.LENGTH_SHORT).show()
+      return
+    }
+
+    MaterialAlertDialogBuilder(requireContext())
+      .setTitle("Copy service password?")
+      .setMessage("Your service password lets anyone who has it send messages as you on the service. Treat it like a password: don't paste it anywhere you don't fully trust. It will be cleared from the clipboard after ${Util.SENSITIVE_CLIPBOARD_TIMEOUT_SECONDS} seconds.")
+      .setPositiveButton("Copy") { _, _ ->
+        Util.copyToClipboardSensitive(requireContext(), servicePassword)
+        Toast.makeText(requireContext(), "Copied service password", Toast.LENGTH_SHORT).show()
+      }
+      .setNegativeButton(android.R.string.cancel, null)
+      .show()
+  }
+
   private fun copyPaymentsDataToClipboard() {
     MaterialAlertDialogBuilder(requireContext())
       .setMessage(