binder: Move FakeDeadBinder to internal

It is only used by internal and isn't for general consumption.

Author: ejona86

binder/src/androidTest/java/io/grpc/binder/internal/BinderClientTransportTest.java

@@ -39,9 +39,9 @@
 import io.grpc.Status.Code;
 import io.grpc.binder.AndroidComponentAddress;
 import io.grpc.binder.BinderServerBuilder;
-import io.grpc.binder.FakeDeadBinder;
 import io.grpc.binder.HostServices;
 import io.grpc.binder.SecurityPolicy;
+import io.grpc.binder.internal.FakeDeadBinder;
 import io.grpc.binder.internal.OneWayBinderProxies.BlackHoleOneWayBinderProxy;
 import io.grpc.binder.internal.OneWayBinderProxies.BlockingBinderDecorator;
 import io.grpc.binder.internal.OneWayBinderProxies.ThrowingOneWayBinderProxy;

binder/src/testFixtures/java/io/grpc/binder/FakeDeadBinder.java renamed to binder/src/testFixtures/java/io/grpc/binder/internal/FakeDeadBinder.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package io.grpc.binder;
+package io.grpc.binder.internal;
 
 import android.os.DeadObjectException;
 import android.os.IBinder;