Nullsafe react/common/build (#45652)

Summary:
Pull Request resolved: #45652

Results of arc nn on the module

Changelog: [Internal]

Reviewed By: arushikesarwani94

Differential Revision: D60188665

fbshipit-source-id: d5322ed15e55a367dc1854177cd533fed90226ee

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/common/ClearableSynchronizedPool.java

@@ -8,11 +8,14 @@
 package com.facebook.react.common;
 
 import androidx.core.util.Pools;
+import com.facebook.infer.annotation.Nullsafe;
+import javax.annotation.Nullable;
 
 /**
  * Like {@link androidx.core.util.Pools.SynchronizedPool} with the option to clear the pool (e.g. on
  * memory pressure).
  */
+@Nullsafe(Nullsafe.Mode.LOCAL)
 public class ClearableSynchronizedPool<T> implements Pools.Pool<T> {
 
   private final Object[] mPool;
@@ -23,7 +26,7 @@ public ClearableSynchronizedPool(int maxSize) {
   }
 
   @Override
-  public synchronized T acquire() {
+  public synchronized @Nullable T acquire() {
     if (mSize == 0) {
       return null;
     }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/common/build/ReactBuildConfig.java

@@ -7,6 +7,7 @@
 
 package com.facebook.react.common.build;
 
+import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.react.BuildConfig;
 
 /**
@@ -15,6 +16,7 @@
  * and b) we don't have to deal with IntelliJ getting confused about the autogenerated BuildConfig
  * class all over the place.
  */
+@Nullsafe(Nullsafe.Mode.LOCAL)
 public class ReactBuildConfig {
 
   public static final boolean DEBUG = BuildConfig.DEBUG;