fix(android): children views were not recycled (#516)

Author: yepMad

android/src/main/java/com/reactnativepagerview/FragmentAdapter.kt

@@ -73,6 +73,10 @@ class FragmentAdapter(fragmentActivity: FragmentActivity) : FragmentStateAdapter
 
   fun getReactChildCount() = childrenViews.size
 
+  fun removeAll() {
+    childrenViews.clear()
+  }
+
   fun removeReactViewAt(index: Int) {
     markDirty()
     childrenViews.removeAt(index)

android/src/main/java/com/reactnativepagerview/PagerViewViewManager.kt

@@ -81,6 +81,12 @@ class PagerViewViewManager : ViewGroupManager<ViewPager2>() {
     adapter.removeReactViewAt(index)
     postNewChanges(parent)
   }
+  
+  override fun removeAllViews(parent: ViewPager2) {
+    val adapter = parent.adapter as FragmentAdapter
+    adapter.removeAll();
+    postNewChanges(parent)
+  }
 
   override fun needsCustomLayoutForChildren(): Boolean {
     return true