Clean up the RestrictTo annotation in Futures

Remove unnecessary RestrictTo annotations for these classes.
The Package-info.java already defined for the visibility scope.

Test: ./gradlew bOS &&
./gradlew camera:camera-core:connectedAndroidTest &&
./gradlew camera:camera-camera2:connectedAndroidTest &&
./gradlew camera:camera-extensions:connectedAndroidTest &&
./gradlew camera:camera-core:test &&
./gradlew camera:camera-camera2:test &&
./gradlew camera:camera-extensions:test &&
./gradlew camera:camera-extensions:connectedAndroidTest &&
./gradlew camera:integration-tests:camera-testapp-extensions:connectedAndroidTest

Change-Id: Icf2e0295bc81809f269f644af8faa2ad20356965

diff --git a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/AsyncFunction.java b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/AsyncFunction.java
index fd275bf..1ffb5e7 100644
--- a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/AsyncFunction.java
+++ b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/AsyncFunction.java

@@ -17,7 +17,6 @@
 package androidx.camera.core.impl.utils.futures;
 
 import androidx.annotation.Nullable;
-import androidx.annotation.RestrictTo;
 
 import com.google.common.util.concurrent.ListenableFuture;
 
@@ -33,12 +32,10 @@
  *
  * @author Chris Povirk
  * @since 11.0
- * @hide
  * @param <I>
  * @param <O>
  */
 @FunctionalInterface
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public interface AsyncFunction<I, O> {
     /**
      * Returns an output {@code Future} to use in place of the given {@code input}. The output

diff --git a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ChainingListenableFuture.java b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ChainingListenableFuture.java
index 2e7987c..ff36dcd 100644
--- a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ChainingListenableFuture.java
+++ b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ChainingListenableFuture.java

@@ -23,7 +23,6 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.annotation.RestrictTo;
 import androidx.camera.core.impl.utils.executor.CameraXExecutors;
 
 import com.google.common.util.concurrent.ListenableFuture;
@@ -50,9 +49,7 @@
  * <p>If the Function throws any checked exceptions, they should be wrapped
  * in a {@code UndeclaredThrowableException} so that this class can get access to the cause.
  *
- * @hide
  */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 class ChainingListenableFuture<I, O> extends FutureChain<O> implements Runnable {
     @Nullable
     private AsyncFunction<? super I, ? extends O> mFunction;

diff --git a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureCallback.java b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureCallback.java
index eaf513d..681271f 100644
--- a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureCallback.java
+++ b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureCallback.java

@@ -17,7 +17,6 @@
 package androidx.camera.core.impl.utils.futures;
 
 import androidx.annotation.Nullable;
-import androidx.annotation.RestrictTo;
 
 import com.google.common.util.concurrent.ListenableFuture;
 
@@ -35,10 +34,8 @@
  *
  * @author Anthony Zana
  * @since 10.0
- * @hide
  * @param <V>
  */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public interface FutureCallback<V> {
     /** Invoked with the result of the {@code Future} computation when it is successful. */
     void onSuccess(@Nullable V result);

diff --git a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureChain.java b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureChain.java
index 6e45548..6cf3de9 100644
--- a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureChain.java
+++ b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/FutureChain.java

@@ -20,7 +20,6 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.annotation.RestrictTo;
 import androidx.arch.core.util.Function;
 import androidx.concurrent.futures.CallbackToFutureAdapter;
 import androidx.core.util.Preconditions;
@@ -41,10 +40,8 @@
  *          .transform(User::getId, directExecutor())
  *          .transform(ActivityService::isLoggedIn, threadPool);
  *  }</pre>
- *  @hide
  *  @param <V>
  */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class FutureChain<V> implements ListenableFuture<V> {
     @NonNull
     private final ListenableFuture<V> mDelegate;

diff --git a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ListFuture.java b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ListFuture.java
index f56b7dd..45cb086 100644
--- a/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ListFuture.java
+++ b/camera/camera-core/src/main/java/androidx/camera/core/impl/utils/futures/ListFuture.java

@@ -22,7 +22,6 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.annotation.RestrictTo;
 import androidx.camera.core.impl.utils.executor.CameraXExecutors;
 import androidx.concurrent.futures.CallbackToFutureAdapter;
 import androidx.core.util.Preconditions;
@@ -49,10 +48,7 @@
  * The idea is to create a (null-filled) List and register a listener with
  * each component future to fill out the value in the List when that future
  * completes.
- *
- * @hide
  */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 class ListFuture<V> implements ListenableFuture<List<V>> {
     @Nullable
     List<? extends ListenableFuture<? extends V>> mFutures;