Add settings item for settings screen

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -386,6 +386,8 @@ public class ConversationActivity extends BriarActivity
 		observeOnce(viewModel.getPrivateMessageFormat(), this, format -> {
 			boolean visible = format == TEXT_IMAGES_AUTO_DELETE;
 			menu.findItem(R.id.action_auto_delete).setVisible(visible);
+			menu.findItem(R.id.action_conversation_settings)
+					.setVisible(visible);
 		});
 
 		return super.onCreateOptionsMenu(menu);
@@ -413,6 +415,9 @@ public class ConversationActivity extends BriarActivity
 				viewModel.setAutoDeleteTimerEnabled(enabled);
 				item.setChecked(enabled);
 				return true;
+			case R.id.action_conversation_settings:
+				// TODO: show settings
+				return true;
 			case R.id.action_delete_all_messages:
 				askToDeleteAllMessages();
 				return true;

briar-android/src/main/res/menu/conversation_actions.xml

@@ -24,6 +24,13 @@
 		app:showAsAction="never"
 		tools:visible="true" />
 
+	<item
+		android:id="@+id/action_conversation_settings"
+		android:title="@string/menu_item_conversation_settings"
+		android:visible="false"
+		app:showAsAction="never"
+		tools:visible="true" />
+
 	<item
 		android:id="@+id/action_delete_all_messages"
 		android:title="@string/delete_all_messages"

briar-android/src/main/res/values/strings.xml

@@ -166,6 +166,7 @@
 	<string name="set_contact_alias_hint">Contact name</string>
 	<string name="set_alias_button">Change</string>
 	<string name="menu_item_auto_delete">Disappearing messages</string>
+	<string name="menu_item_conversation_settings">Conversation settings</string>
 	<string name="delete_all_messages">Delete all messages</string>
 	<string name="dialog_title_delete_all_messages">Confirm Message Deletion</string>
 	<string name="dialog_message_delete_all_messages">Are you sure that you want to delete all messages?</string>