message: add random_uniform benchmark for default setting
  The default setting of range [0,1) on float is commonly used, add a benchmark for it
diff: @@ -858,6 +858,16 @@ class MicroBenchmarks(test.Benchmark):
  self._benchmark_tf_random_uniform_2_by_2(
  dtype=dtypes.float32, device=GPU)
  + def benchmark_tf_random_uniform_2_by_2_default_setting_CPU(self):
  + with context.device(CPU):
  + func = lambda: random_ops.random_uniform((2, 2))
  + self._run(func, num_iters=self._num_iters_2_by_2)
  +
  + def benchmark_tf_random_uniform_2_by_2_default_setting_GPU(self):
  + with context.device(GPU):
  + func = lambda: random_ops.random_uniform((2, 2))
  + self._run(func, num_iters=self._num_iters_2_by_2)
  +
  def _benchmark_transpose(self,
  m,
  num_iters,
  