[speech-to-text] RecognizeOptions does not support character_insertion_bias

[Festlandtommy]

When using custom parameters for STT recognize, such as BackgroundAudioSuppression, MaxAlternatives I noticed there is no setter forCharacterInsertionBias.

Possible solution:

// SetCharacterInsertionBias : Allow user to set CharacterInsertionBias
func (_options *RecognizeOptions) SetCharacterInsertionBias(characterInsertionBias float32) *RecognizeOptions {
	_options.CharacterInsertionBias = core.Float32Ptr(characterInsertionBias)
	return _options
}