Fix NPE in JmeAndroidSystem when audio renderer is disabled (#2670)

* Initial plan

* Fix null audio renderer NPE in JmeAndroidSystem

Agent-Logs-Url: https://github.com/jMonkeyEngine/jmonkeyengine/sessions/a0e02d04-8d68-4b0f-aab6-0cc86f24d418

Co-authored-by: riccardobl <4943530+riccardobl@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: riccardobl <4943530+riccardobl@users.noreply.github.com>

Author: Copilot

jme3-android/src/main/java/com/jme3/system/android/JmeAndroidSystem.java

@@ -76,7 +76,9 @@ public void writeImageFile(OutputStream outStream, String format, ByteBuffer ima
 
     @Override
     public JmeContext newContext(AppSettings settings, Type contextType) {
-        if (settings.getAudioRenderer().equals(AppSettings.ANDROID_MEDIAPLAYER)) {
+        if (settings.getAudioRenderer() == null) {
+            audioRendererType = null;
+        } else if (settings.getAudioRenderer().equals(AppSettings.ANDROID_MEDIAPLAYER)) {
             audioRendererType = AppSettings.ANDROID_MEDIAPLAYER;
         } else if (settings.getAudioRenderer().equals(AppSettings.ANDROID_OPENAL_SOFT)) {
             audioRendererType = AppSettings.ANDROID_OPENAL_SOFT;
@@ -92,6 +94,9 @@ public JmeContext newContext(AppSettings settings, Type contextType) {
 
     @Override
     public AudioRenderer newAudioRenderer(AppSettings settings) {
+        if (settings.getAudioRenderer() == null) {
+            return null;
+        }
         ALC alc = new AndroidALC();
         AL al = new AndroidAL();
         EFX efx = new AndroidEFX();