fix: avoid Polygon crash on empty list of points (#667)

Fixes #666

Co-authored-by: Uli Bubenheimer <[email protected]>

Author: bubenheimer

app/src/main/java/com/google/maps/android/compose/markerexamples/draggablemarkerscollectionwithpolygon/DraggableMarkersCollectionWithPolygonActivity.kt

@@ -187,9 +187,7 @@ private fun LocationMarker(
 private fun Polygon(markerPositionsModel: () -> List<() -> LatLng>) {
     val movingMarkerPositions = markerPositionsModel()
 
-    if (movingMarkerPositions.isNotEmpty()) {
-        val markerPositions = movingMarkerPositions.map { it() }
+    val markerPositions = movingMarkerPositions.map { it() }
 
-        Polygon(markerPositions)
-    }
+    Polygon(markerPositions)
 }

maps-compose/src/main/java/com/google/maps/android/compose/Polygon.kt

@@ -68,6 +68,8 @@ public fun Polygon(
     zIndex: Float = 0f,
     onClick: (Polygon) -> Unit = {}
 ) {
+    if (points.isEmpty()) return // avoid SDK crash
+
     val mapApplier = currentComposer.applier as MapApplier?
     ComposeNode<PolygonNode, MapApplier>(
         factory = {