AnnotationManagerImpl memory leak (#10999)

https://mapbox.atlassian.net/browse/MAPSAND-2594

## Summary

- Fix native memory leak where bitmap style images added by
PointAnnotation were never removed from the style when annotations were
deleted via delete(), deleteAll(), or onDestroy().
- Add removeIconFromStyle / removeIconsFromStyle helpers that clean up
style images with the ICON_DEFAULT_NAME_PREFIX prefix, matching the
existing addIconToStyle counterpart.
- The cleanup only targets auto-generated images (prefixed with
icon_default_name_) so user-managed style images are unaffected.

cc @mapbox/maps-android

cc @mapbox/sdk-platform

GitOrigin-RevId: 96531e5cdc0799404169ca092b520c759e16071a

Author: kediarov

CHANGELOG.md

@@ -5,6 +5,8 @@ Mapbox welcomes participation and contributions from everyone.
 > **16 KB Page Size Support:** Starting with version 11.7.0 and 10.19.0, **NDK 27 is supported** with dedicated artifacts that include [support for 16 KB page sizes](https://developer.android.com/guide/practices/page-sizes). If your app does not require 16 KB page size support, you can keep using our default artifacts without `-ndk27` suffix. For more information about our NDK support, see https://docs.mapbox.com/android/maps/guides/#ndk-support
 
 # main
+## Bug fixes 🐞
+* Fix native memory leak in `AnnotationManager` where bitmap style images were not removed onDestroy.
 
 # 11.20.0-rc.1 March 03, 2026
 

plugin-annotation/src/main/java/com/mapbox/maps/plugin/annotation/AnnotationManagerImpl.kt

@@ -647,6 +647,18 @@ internal constructor(
     delegateProvider.mapStyleManagerDelegate.addImage(image(imageId, bitmap))
   }
 
+  private fun removeIconsFromStyle(style: MapboxStyleManager, annotations: Collection<T>) {
+    annotations.forEach { removeIconFromStyle(style, it) }
+  }
+
+  private fun removeIconFromStyle(style: MapboxStyleManager, annotation: T) {
+    val symbol = annotation as? PointAnnotation ?: return
+    val imageId = symbol.iconImage ?: return
+    if (!imageId.startsWith(PointAnnotation.ICON_DEFAULT_NAME_PREFIX)) return
+    if (!style.hasStyleImage(imageId)) return
+    style.removeStyleImage(imageId)
+  }
+
   // Add icons to style from PointAnnotation.
   private fun addIconToStyle(style: MapboxStyleManager, annotations: Collection<T>) {
     // Add icon image bitmap from point annotation
@@ -762,6 +774,7 @@ internal constructor(
         style.removeStyleSource(it)
       }
     }
+    removeIconsFromStyle(style, annotations)
 
     unregisterInteractions()
     annotationMap.clear()