message: [TF:XLA] Don't remove TF_XLA_FLAGS when enabling autojit in _xla_gpu tests.
  Previously, the environment variable was overwritten with the test specific flags. Now they are concatenated together.
diff: @@ -1489,7 +1489,8 @@ class TensorFlowTestCase(googletest.TestCase):
  if is_xla_enabled():
  os.putenv(
  "TF_XLA_FLAGS", "--tf_xla_auto_jit=2 --tf_xla_min_cluster_size=1 "
  - "--tf_xla_enable_lazy_compilation=false")
  + "--tf_xla_enable_lazy_compilation=false " +
  + os.getenv("TF_XLA_FLAGS", ""))
  self._threads = []
  self._tempdir = None
  self._cached_session = None
  