Android: Switch dpad default to use HAT X/Y +/- instead of "dpad", as documented.

Add a simple "autoconfigure" facility for input devices, that lets the user choose
if several are connected.

Can be expanded in the future to provide custom default mapppings for various devices as long as we manage to identify them.

Ideally, key mappings should be unique per device but they aren't yet.

UI/ControlMappingScreen.cpp

@@ -199,6 +199,9 @@ void ControlMappingScreen::CreateViews() {
 	LinearLayout *leftColumn = new LinearLayout(ORIENT_VERTICAL, new LinearLayoutParams(200, FILL_PARENT));
 	leftColumn->Add(new Choice(k->T("Clear All")))->OnClick.Handle(this, &ControlMappingScreen::OnClearMapping);
 	leftColumn->Add(new Choice(k->T("Default All")))->OnClick.Handle(this, &ControlMappingScreen::OnDefaultMapping);
+	if (KeyMap::GetSeenPads().size()) {
+		leftColumn->Add(new Choice(k->T("Autoconfigure")))->OnClick.Handle(this, &ControlMappingScreen::OnAutoConfigure);
+	}
 	leftColumn->Add(new Spacer(new LinearLayoutParams(1.0f)));
 	leftColumn->Add(new Choice(d->T("Back")))->OnClick.Handle<UIScreen>(this, &UIScreen::OnBack);
 
@@ -238,6 +241,24 @@ UI::EventReturn ControlMappingScreen::OnDefaultMapping(UI::EventParams &params)
 	return UI::EVENT_DONE;
 }
 
+UI::EventReturn ControlMappingScreen::OnAutoConfigure(UI::EventParams &params) {
+	std::vector<std::string> items;
+	for (auto s : KeyMap::GetSeenPads()) {
+		items.push_back(s);
+	}
+	ListPopupScreen *autoConfList = new ListPopupScreen("Autoconfigure for device", items, -1);
+	screenManager()->push(autoConfList);
+	return UI::EVENT_DONE;
+}
+
+void ControlMappingScreen::dialogFinished(const Screen *dialog, DialogResult result) {
+	if (result == DR_OK && dialog->tag() == "listpopup") {
+		ListPopupScreen *popup = (ListPopupScreen *)dialog;
+		KeyMap::AutoConfForPad(popup->GetChoiceString());
+		RecreateViews();
+	}
+}
+
 void KeyMappingNewKeyDialog::CreatePopupContents(UI::ViewGroup *parent) {
 	using namespace UI;