Remove support for Android API < 23 in ReactViewManager (facebook#39678)

Summary:
Pull Request resolved: facebook#39678

Since minsdk version was increased to 23, we are deleting code using Android APIs < 23 for class ReactViewManager

changelog: [Android][Breaking] Remove support for Android API < 23 in ReactViewManager

Reviewed By: NickGerleman

Differential Revision: D48545513

fbshipit-source-id: 7c57a9ea850c0de012912a6454e8c282088e8b25

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewManager.java

@@ -7,9 +7,7 @@
 
 package com.facebook.react.views.view;
 
-import android.annotation.TargetApi;
 import android.graphics.Rect;
-import android.os.Build;
 import android.view.View;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -203,7 +201,6 @@ public void setNativeBackground(ReactViewGroup view, @Nullable ReadableMap bg) {
             : ReactDrawableHelper.createDrawableFromJSDescription(view.getContext(), bg));
   }
 
-  @TargetApi(Build.VERSION_CODES.M)
   @ReactProp(name = "nativeForegroundAndroid")
   public void setNativeForeground(ReactViewGroup view, @Nullable ReadableMap fg) {
     view.setForeground(