Fix up aio interop client

src/python/grpcio_tests/tests/interop/BUILD.bazel

@@ -12,8 +12,8 @@ py_library(
     ],
 )
 
-py_binary(
-    name = "client",
+py_library(
+    name = "client_lib",
     srcs = ["client.py"],
     imports = ["../../"],
     deps = [
@@ -25,6 +25,13 @@ py_binary(
     ],
 )
 
+py_binary(
+    name = "client",
+    srcs = ["client.py"],
+    deps = [":client_lib"],
+    python_version = "PY3",
+)
+
 py_library(
     name = "methods",
     srcs = ["methods.py"],

src/python/grpcio_tests/tests_aio/interop/BUILD.bazel

@@ -62,7 +62,6 @@ py_binary(
     ],
 )
 
-# TODO: Pull out library to fix aio interop client.
 py_binary(
     name = "client",
     srcs = ["client.py"],
@@ -71,7 +70,8 @@ py_binary(
     deps = [
         ":methods",
         "//src/python/grpcio/grpc:grpcio",
-        "//src/python/grpcio_tests/tests/interop:client",
+        "//src/python/grpcio_tests/tests/interop:client_lib",
         "//src/python/grpcio_tests/tests/interop:resources",
     ],
 )
+