Migrate Nullable and NonNull annotations to AndroidX

Summary:
This diff migrates the usages Nullable and NonNull annotations to AndroidX instead of javax.

The purpose of this change is to bring consistency in the annotations used by the core of RN

Reviewed By: makovkastar

Differential Revision: D16054504

fbshipit-source-id: 21d888854da088d2a14615a90d4dc058e5286b91

ReactAndroid/src/main/java/com/facebook/react/bridge/ReadableNativeArray.java

@@ -6,13 +6,13 @@
  */
 package com.facebook.react.bridge;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.jni.HybridData;
 import com.facebook.proguard.annotations.DoNotStrip;
 import java.util.ArrayList;
 import java.util.Arrays;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 /**
  * Implementation of a NativeArray that allows read-only access to its members. This will generally
@@ -112,12 +112,12 @@ public class ReadableNativeArray extends NativeArray implements ReadableArray {
   }
 
   @Override
-  public @Nonnull ReadableType getType(int index) {
+  public @NonNull ReadableType getType(int index) {
     return getLocalTypeArray()[index];
   }
 
   @Override
-  public @Nonnull Dynamic getDynamic(int index) {
+  public @NonNull Dynamic getDynamic(int index) {
     return DynamicFromArray.create(this, index);
   }
 
@@ -136,7 +136,7 @@ public class ReadableNativeArray extends NativeArray implements ReadableArray {
   }
 
   @Override
-  public @Nonnull ArrayList<Object> toArrayList() {
+  public @NonNull ArrayList<Object> toArrayList() {
     ArrayList<Object> arrayList = new ArrayList<>();
 
     for (int i = 0; i < this.size(); i++) {