testing: Stabilize GrpcCleanupRule, GrpcServerRule (#10494)

Closes #2488.

Author: sergiitk

Diff for: testing/src/main/java/io/grpc/testing/GrpcCleanupRule.java

@@ -23,7 +23,6 @@
 import com.google.common.base.Stopwatch;
 import com.google.common.base.Ticker;
 import com.google.common.collect.Lists;
-import io.grpc.ExperimentalApi;
 import io.grpc.ManagedChannel;
 import io.grpc.Server;
 import java.util.ArrayList;
@@ -70,7 +69,6 @@
  *
  * @since 1.13.0
  */
-@ExperimentalApi("https://github.com/grpc/grpc-java/issues/2488")
 @NotThreadSafe
 public final class GrpcCleanupRule extends ExternalResource {
 

Diff for: testing/src/main/java/io/grpc/testing/GrpcServerRule.java

@@ -19,7 +19,6 @@
 import static com.google.common.base.Preconditions.checkState;
 
 import io.grpc.BindableService;
-import io.grpc.ExperimentalApi;
 import io.grpc.ManagedChannel;
 import io.grpc.Server;
 import io.grpc.ServerServiceDefinition;
@@ -48,7 +47,6 @@
  * <p>An {@link AbstractStub} can be created against this service by using the
  * {@link ManagedChannel} provided by {@link GrpcServerRule#getChannel()}.
  */
-@ExperimentalApi("https://github.com/grpc/grpc-java/issues/2488")
 public final class GrpcServerRule extends ExternalResource {
 
   private ManagedChannel channel;