Avoid creating anonymous objects when rendering view annotations (#6263)

While doing some measurements I noticed that when we are showing view
annotations we create objects on every frame:
<img width="3008" height="1667" alt="Screenshot 2025-09-03 at 16 16 04"
src="https://github.com/user-attachments/assets/27200dc0-4235-4b60-807f-412d5e21dee8"
/>

This PR avoids creating those objects due to the swapBuffers call.

cc @mapbox/maps-android

GitOrigin-RevId: 15e2c7286e9ac02781f01a679742c11cd0164474

Author: jush

maps-sdk/src/main/java/com/mapbox/maps/renderer/MapboxRenderThread.kt

@@ -370,6 +370,11 @@ internal class MapboxRenderThread : Choreographer.FrameCallback {
     GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, 0)
   }
 
+  /**
+   * Keep a [Choreographer.FrameCallback] to [swapBuffers] to avoid creating a new one on every time.
+   */
+  private val swapBuffersFunc = Choreographer.FrameCallback { swapBuffers() }
+
   @OptIn(MapboxExperimental::class)
   private fun draw(frameTimeNanos: Long) {
     if (!fpsManager.preRender(frameTimeNanos, renderThreadStatsRecorder?.isRecording == true)) {
@@ -407,9 +412,7 @@ internal class MapboxRenderThread : Choreographer.FrameCallback {
       // when we're syncing view annotations with the map -
       // we swap buffers the next frame to achieve better synchronization with view annotations update
       // that always happens 1 frame later
-      Choreographer.getInstance().postFrameCallback {
-        swapBuffers()
-      }
+      Choreographer.getInstance().postFrameCallback(swapBuffersFunc)
       // explicit flush as we will not be doing any drawing until buffer swap for the next frame -
       // we send commands to GPU this frame as we should have some free time and perform buffer swap asap on the next frame
       // note that this doesn't block the calling thread, it merely signals the driver that we might not be sending any additional commands.