Enable transition for "home" in RecipientPreferencesActivity.

Fixes #3523
Closes #3701
//FREEBIE

src/org/thoughtcrime/securesms/RecipientPreferenceActivity.java

@@ -98,7 +98,9 @@ public class RecipientPreferenceActivity extends PassphraseRequiredActionBarActi
   public boolean onOptionsItemSelected(MenuItem item) {
     super.onOptionsItemSelected(item);
     switch (item.getItemId()) {
-      case android.R.id.home: finish(); return true;
+      case android.R.id.home:
+        super.onBackPressed();
+        return true;
     }
 
     return false;