Fix SpotBugs null pointer dereference warnings

Addressed 12 SpotBugs "Possible null pointer dereference" warnings across 8 files:
- CodenameOneImplementation.java: Fixed null usage in captureAudio logging and data check.
- InteractionDialog.java: Added explicit null checks for Component and Rectangle arguments in showPopupDialog.
- SimpleDateFormat.java: Added return statements to throwInvalid calls.
- HashtableContent.java: Added null check for node.
- Form.java: Added null checks for components in layered pane iteration and safely handled null Class argument in getLayeredPane.
- DefaultLookAndFeel.java: Added null checks for badgeStyle.
- SpinnerNode.java: Added null check for selectionListeners before calling isEmpty().
- CommonTransitions.java: Added default case to switch statement.

Author: google-labs-jules[bot]

CodenameOne/src/com/codename1/components/InteractionDialog.java

@@ -630,7 +630,10 @@ public void showPopupDialog(Component c) {
      *             This is ignored if there isn't enough space
      */
     public void showPopupDialog(Component c, boolean bias) {
-        Form f = c == null ? null : c.getComponentForm(); // PMD Fix: BrokenNullCheck
+        if (c == null) {
+            throw new IllegalArgumentException("Component cannot be null");
+        }
+        Form f = c.getComponentForm(); // PMD Fix: BrokenNullCheck
         if (f != null && !formMode && !f.getContentPane().contains(c)) {
             setFormMode(true);
         }

CodenameOne/src/com/codename1/ui/Form.java

@@ -1435,15 +1435,17 @@ public Container getLayeredPane(Class c, boolean top) {
                 }
             }
         }
-        String n = c.getName();
+        String n = c != null ? c.getName() : null;
         // NOTE: We need to use getChildrenAsList(true) rather than simply iterating
         // over layeredPaneImpl because the latter won't find components while an animation
         // is in progress.... We could end up adding a whole bunch of layered panes
         // by accident
         java.util.List<Component> children = layeredPaneImpl.getChildrenAsList(true);
-        for (Component cmp : children) {
-            if (cmp != null && n.equals(cmp.getClientProperty("cn1$_cls"))) {
-                return (Container) cmp;
+        if (n != null) {
+            for (Component cmp : children) {
+                if (cmp != null && n.equals(cmp.getClientProperty("cn1$_cls"))) {
+                    return (Container) cmp;
+                }
             }
         }
 
@@ -1496,15 +1498,17 @@ public Container getLayeredPane(Class c, int zIndex) {
                 }
             }
         }
-        String n = c.getName();
+        String n = c != null ? c.getName() : null;
         // NOTE: We need to use getChildrenAsList(true) rather than simply iterating
         // over layeredPaneImpl because the latter won't find components while an animation
         // is in progress.... We could end up adding a whole bunch of layered panes
         // by accident
         java.util.List<Component> children = layeredPaneImpl.getChildrenAsList(true);
-        for (Component cmp : children) {
-            if (cmp != null && n.equals(cmp.getClientProperty("cn1$_cls"))) {
-                return (Container) cmp;
+        if (n != null) {
+            for (Component cmp : children) {
+                if (cmp != null && n.equals(cmp.getClientProperty("cn1$_cls"))) {
+                    return (Container) cmp;
+                }
             }
         }