previous conviction shall be charged in the accusatory pleading. If two or more of the previous convictions are found to be true by the jury, upon a jury trial, or by the court, upon a court trial, or are admitted by the defendant, the defendant shall be imprisoned in the county jail for a period of not less than 90 days. The trial court may grant probation or suspend the execution of sentence imposed upon the defendant if the court, as a condition of the probation or suspension, orders the defendant to spend 60 days in an alcohol treatment and recovery program in a facility which, as a minimum, meets the standards described in the guidelines for alcoholic recovery home programs issued by the Division of Alcohol Programs of the Department of Alcohol and Drug Abuse.