fix(android): child argument types in addView methods (#857)

Author: szydlovsky

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

@@ -88,7 +88,7 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>(), RNCViewPa
         return host
     }
 
-    override fun addView(host: NestedScrollableHost, child: View?, index: Int) {
+    override fun addView(host: NestedScrollableHost, child: View, index: Int) {
         PagerViewViewManagerImpl.addView(host, child, index)
     }
 

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

@@ -69,7 +69,7 @@ class PagerViewViewManager : ViewGroupManager<NestedScrollableHost>() {
         return host
     }
 
-    override fun addView(host: NestedScrollableHost, child: View?, index: Int) {
+    override fun addView(host: NestedScrollableHost, child: View, index: Int) {
         PagerViewViewManagerImpl.addView(host, child, index)
     }