Make metadata field mandatory for program info struct.

    ALOGV("%s", __FUNCTION__);

    int jStatus;

    jobject jMetadata = NULL;

    if (nProgramInfo->metadata != NULL) {

        ALOGV("%s metadata %p", __FUNCTION__, nProgramInfo->metadata);

    if (nProgramInfo == nullptr || nProgramInfo->metadata == nullptr) {

        return (jint)RADIO_STATUS_BAD_VALUE;

    }

    jStatus = convertMetadataFromNative(env, &jMetadata, nProgramInfo->metadata);

    if (jStatus < 0) {

        return jStatus;

    }

    }

    ALOGV("%s channel %d tuned %d", __FUNCTION__, nProgramInfo->channel, nProgramInfo->tuned);