[6.7.0][HDMap][Overlay] 优化地图marker的处理逻辑；当地图控件从窗口中移除时，断开Java层与Marker之间的引用，规避内存泄露

libraries/mogo-map/src/main/java/com/mogo/map/overlay/MoGoOverlayManagerImpl.kt

@@ -458,4 +458,13 @@ internal class MoGoOverlayManagerImpl: IMoGoOverlayManager {
     override fun updateAnimPoint(options: Options, mapTag:String) {
         mapInstance.getMogoMap(mapTag)?.addAnimPoint(options)
     }
+
+    override fun clear() {
+        synchronized(points) {
+            points.clear()
+        }
+        synchronized(lines) {
+            lines.clear()
+        }
+    }
 }