Update TTS plugin interface to receive engine configuration data

namespace android {

#define ANDROID_TTS_ENGINE_PROPERTY_CONFIG "engineConfig"

#define ANDROID_TTS_ENGINE_PROPERTY_PITCH  "pitch"

#define ANDROID_TTS_ENGINE_PROPERTY_RATE   "rate"

#define ANDROID_TTS_ENGINE_PROPERTY_VOLUME "volume"

enum tts_synth_status {

    TTS_SYNTH_DONE              = 0,

    TTS_SYNTH_PENDING           = 1

    // Initialize the TTS engine and returns whether initialization succeeded.

    // @param synthDoneCBPtr synthesis callback function pointer

    // @return TTS_SUCCESS, or TTS_FAILURE

    virtual tts_result init(synthDoneCB_t synthDoneCBPtr);

    virtual tts_result init(synthDoneCB_t synthDoneCBPtr, const char *engineConfig);

    // Shut down the TTS engine and releases all associated resources.

    // @return TTS_SUCCESS, or TTS_FAILURE

    virtual tts_result synthesizeText(const char *text, int8_t *buffer,

            size_t bufferSize, void *userdata);

    // Synthesize IPA text.

    // As the synthesis is performed, the engine invokes the callback to notify

    // the TTS framework that it has filled the given buffer, and indicates how

    // many bytes it wrote. The callback is called repeatedly until the engine

    // has generated all the audio data corresponding to the IPA data.

    // @param ipa      the IPA data to synthesize

    // @param userdata  pointer to be returned when the call is invoked

    // @param buffer    the location where the synthesized data must be written

    // @param bufferSize the number of bytes that can be written in buffer

    // @return TTS_FEATURE_UNSUPPORTED if IPA is not supported,

    //         otherwise TTS_SUCCESS or TTS_FAILURE

    virtual tts_result synthesizeIpa(const char *ipa, int8_t *buffer,

            size_t bufferSize, void *userdata);

};

} // namespace android