message: Fix type mismatch error in freq_mask and time_mask
  * Fix type mismatch error in freq_mask
  This PR fixes type mismatch error in freq_mask, reported in issue 1158 (credit to BryanWBear)
  * fix type mismatch in time_mask
  * Update audio_ops.py
diff: @@ -273,6 +273,7 @@ def freq_mask(input, param, name=None):
  Returns:
  A tensor of spectrogram.
  """
  + input = tf.convert_to_tensor(input)
  # TODO: Support audio with channel > 1.
  freq_max = tf.shape(input)[1]
  f = tf.random.uniform(shape=(), minval=0, maxval=param, dtype=tf.dtypes.int32)
  @@ -283,7 +284,7 @@ def freq_mask(input, param, name=None):
  condition = tf.math.logical_and(
  tf.math.greater_equal(indices, f0), tf.math.less(indices, f0 + f)
  )
  - return tf.where(condition, 0, input)
  + return tf.where(condition, tf.cast(0, input.dtype), input)
  def time_mask(input, param, name=None):
  @@ -297,6 +298,7 @@ def time_mask(input, param, name=None):
  Returns:
  A tensor of spectrogram.
  """
  + input = tf.convert_to_tensor(input)
  # TODO: Support audio with channel > 1.
  time_max = tf.shape(input)[0]
  t = tf.random.uniform(shape=(), minval=0, maxval=param, dtype=tf.dtypes.int32)
  @@ -307,7 +309,7 @@ def time_mask(input, param, name=None):
  condition = tf.math.logical_and(
  tf.math.greater_equal(indices, t0), tf.math.less(indices, t0 + t)
  )
  - return tf.where(condition, 0, input)
  + return tf.where(condition, tf.cast(0, input.dtype), input)
  def fade(input, fade_in, fade_out, mode, name=None):
  