message: Use context.config instead of a clean tf.ConfigProto in test_util
diff: @@ -49,7 +49,6 @@ from google.protobuf import descriptor_pool
  from google.protobuf import text_format
  from tensorflow.core.framework import graph_pb2
  -from tensorflow.core.protobuf import config_pb2
  from tensorflow.core.protobuf import rewriter_config_pb2
  from tensorflow.python import pywrap_tensorflow
  from tensorflow.python import tf2
  @@ -2741,12 +2740,10 @@ class TensorFlowTestCase(googletest.TestCase):
  # will be used even when a specific device is supposed to be used.
  allow_soft_placement = not force_gpu
  if config is None:
  - config = config_pb2.ConfigProto()
  + config = context.context().config
  config.allow_soft_placement = allow_soft_placement
  - config.gpu_options.per_process_gpu_memory_fraction = 0.3
  elif not allow_soft_placement and config.allow_soft_placement:
  - config_copy = config_pb2.ConfigProto()
  - config_copy.CopyFrom(config)
  + config_copy = context.context().config
  config = config_copy
  config.allow_soft_placement = False
  # Don't perform optimizations for tests so we don't inadvertently run
  