Update install_mysql.sh (#12101)
Update install_mysql.sh (#12101)

After Debian 9 and according to the manual https://manpages.debian.org/stretch/apt/apt-key.8.en.html, after Debian 9  instead of using "apt-key add" a keyring should be placed directly in the /etc/apt/trusted.gpg.d/ directory with a descriptive name and either "gpg" or "asc" as file extension. Also added better redirection on the apt-key list command.
Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,sekikn/incubator-airflow,dhuang/incubator-airflow,mrkm4ntr/incubator-airflow,danielvdende/incubator-airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,nathanielvarona/airflow,mrkm4ntr/incubator-airflow,mistercrunch/airflow,bolkedebruin/airflow,cfei18/incubator-airflow,apache/airflow,apache/incubator-airflow,sekikn/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,airbnb/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,apache/airflow,cfei18/incubator-airflow,bolkedebruin/airflow,dhuang/incubator-airflow,sekikn/incubator-airflow,airbnb/airflow,airbnb/airflow,lyft/incubator-airflow,lyft/incubator-airflow,DinoCow/airflow,mistercrunch/airflow,DinoCow/airflow,apache/incubator-airflow,nathanielvarona/airflow,mrkm4ntr/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,apache/airflow,apache/airflow,apache/incubator-airflow,bolkedebruin/airflow,DinoCow/airflow,airbnb/airflow,mrkm4ntr/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,apache/airflow,mistercrunch/airflow,apache/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,dhuang/incubator-airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,apache/airflow,DinoCow/airflow,dhuang/incubator-airflow