Enable the disabled test in b/134670856.

PiperOrigin-RevId: 292646148
Change-Id: Ieaa51721c20fd56b9980bdedc95755c8687daa96

tensorflow/python/keras/distribute/BUILD

@@ -213,7 +213,7 @@ distribute_py_test(
     srcs = ["keras_image_model_correctness_test.py"],
     full_precision = True,
     main = "keras_image_model_correctness_test.py",
-    shard_count = 8,
+    shard_count = 16,
     tags = [
         "multi_and_single_gpu",
         "no_rocm",  # times out on ROCm