Add UI Automator test for verifying 'Commons' app language option in system settings

This commit introduces a UI Automator test in the 'AppLanguagesSystemTest.java' file under the 'fr.free.nrw.commons.ui' package. The test verifies the following:
- Navigates through Android system settings.
- Scrolls to and selects 'Languages & input'.
- Opens 'App languages' and checks if the 'Commons' app appears in the list.
The test uses UiScrollable and UiSelector to find and interact with system UI elements.

app/src/androidTest/java/fr/free/nrw/commons/ui/AppLanguagesSystemTest.java

@@ -0,0 +1,58 @@
+package fr.free.nrw.commons.ui;
+
+import androidx.test.uiautomator.UiScrollable;
+import androidx.test.uiautomator.UiSelector;
+import androidx.test.uiautomator.UiObject;
+import androidx.test.uiautomator.UiDevice;
+import androidx.test.platform.app.InstrumentationRegistry;
+import android.content.Intent;
+import android.provider.Settings;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class AppLanguagesSystemTest {
+
+    private UiDevice device;
+
+    @Before
+    public void setUp() {
+        // Initiate UI Automator
+        device = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());
+
+        // Use Intent to start system application
+        Intent intent = new Intent(Settings.ACTION_SETTINGS);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        InstrumentationRegistry.getInstrumentation().getContext().startActivity(intent);
+
+        // wait Settings starting
+        device.waitForIdle();
+    }
+
+    @Test
+    public void testCommonsAppLanguageOptionExists() throws Exception {
+        // 1. Find and click "System"
+        UiScrollable settingsList = new UiScrollable(new UiSelector().scrollable(true));
+        UiObject systemOption = settingsList.getChildByText(new UiSelector().text("System"), "System");
+        systemOption.click();
+
+        // 2. scroll and find "Languages & input"
+        UiObject languagesInputOption = device.findObject(new UiSelector()
+            .className("android.widget.TextView")
+            .textContains("Gboard"));
+        languagesInputOption.clickAndWaitForNewWindow();
+
+
+
+
+        // 3. detect "App languages" and click
+        UiObject appLanguagesOption = device.findObject(new UiSelector().text("App languages"));
+        appLanguagesOption.clickAndWaitForNewWindow();
+
+        // 4. detect "Commons" APP is there
+        UiScrollable appLanguagesList = new UiScrollable(new UiSelector().scrollable(true));
+        UiObject commonsAppOption = appLanguagesList.getChildByText(new UiSelector().text("Commons"), "Commons");
+
+        assert(commonsAppOption.exists());
+    }
+}