Address code review feedback

- Reuse LinkAccessibilityDelegate instance instead of creating new one each time
- Add detailed comment explaining the magic number for action IDs
- Improves performance by avoiding unnecessary object allocations

Co-authored-by: adbenitez <24558636+adbenitez@users.noreply.github.com>

src/main/java/org/thoughtcrime/securesms/ConversationItem.java

@@ -126,6 +126,7 @@ public class ConversationItem extends BaseConversationItem
   private           Stub<VcardView>                 vcardViewStub;
   private           Stub<CallItemView>              callViewStub;
   private @Nullable EventListener                   eventListener;
+  private @Nullable LinkAccessibilityDelegate       linkAccessibilityDelegate;
 
   private int measureCalls;
 
@@ -432,7 +433,10 @@ public class ConversationItem extends BaseConversationItem
       
       // Set accessibility delegate for TalkBack to expose links as custom actions
       if (Util.isTouchExplorationEnabled(context) && batchSelected.isEmpty()) {
-        bodyText.setAccessibilityDelegate(new LinkAccessibilityDelegate(context));
+        if (linkAccessibilityDelegate == null) {
+          linkAccessibilityDelegate = new LinkAccessibilityDelegate(context);
+        }
+        bodyText.setAccessibilityDelegate(linkAccessibilityDelegate);
       } else {
         bodyText.setAccessibilityDelegate(null);
       }

src/main/java/org/thoughtcrime/securesms/util/LinkAccessibilityDelegate.java

@@ -20,7 +20,10 @@ import java.util.Map;
  */
 public class LinkAccessibilityDelegate extends View.AccessibilityDelegate {
   
-  // Base ID for custom link actions (using a high number to avoid conflicts)
+  // Base ID for custom link actions. Using a high number (0x00FF0000, which is 16,711,680 in decimal)
+  // to avoid conflicts with Android's standard accessibility action IDs, which are typically small integers
+  // (e.g., ACTION_CLICK = 16, ACTION_LONG_CLICK = 32, etc.) or specific bit flags.
+  // This range is safe for custom actions as per Android accessibility guidelines.
   private static final int LINK_ACTION_BASE_ID = 0x00FF0000;
   
   // Map to store span references for each action ID