[AIRFLOW-4434] Support Impala with the HiveServer2Hook (#5206)
[AIRFLOW-4434] Support Impala with the HiveServer2Hook (#5206)

Fix support for impala in hive hook through a config option
that turns off set variable commands. Breaking changes were
introduced in [AIRFLOW-2463].
cfei18/incubator-airflow,wooga/airflow,r39132/airflow,spektom/incubator-airflow,Acehaidrey/incubator-airflow,mrkm4ntr/incubator-airflow,r39132/airflow,cfei18/incubator-airflow,DinoCow/airflow,apache/airflow,mistercrunch/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,mrkm4ntr/incubator-airflow,nathanielvarona/airflow,apache/airflow,airbnb/airflow,DinoCow/airflow,wooga/airflow,apache/incubator-airflow,dhuang/incubator-airflow,dhuang/incubator-airflow,r39132/airflow,sekikn/incubator-airflow,Acehaidrey/incubator-airflow,apache/incubator-airflow,apache/airflow,mrkm4ntr/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,nathanielvarona/airflow,bolkedebruin/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,mistercrunch/airflow,danielvdende/incubator-airflow,dhuang/incubator-airflow,sekikn/incubator-airflow,lyft/incubator-airflow,Fokko/incubator-airflow,wileeam/airflow,apache/incubator-airflow,lyft/incubator-airflow,r39132/airflow,Acehaidrey/incubator-airflow,mtagle/airflow,mistercrunch/airflow,airbnb/airflow,Fokko/incubator-airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,wileeam/airflow,wileeam/airflow,spektom/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,dhuang/incubator-airflow,apache/airflow,danielvdende/incubator-airflow,DinoCow/airflow,mtagle/airflow,cfei18/incubator-airflow,apache/airflow,sekikn/incubator-airflow,Fokko/incubator-airflow,airbnb/airflow,spektom/incubator-airflow,airbnb/airflow,Fokko/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow,DinoCow/airflow,cfei18/incubator-airflow,mtagle/airflow,spektom/incubator-airflow,wooga/airflow,nathanielvarona/airflow,bolkedebruin/airflow,lyft/incubator-airflow,wileeam/airflow,wooga/airflow,nathanielvarona/airflow,bolkedebruin/airflow,apache/airflow,sekikn/incubator-airflow,bolkedebruin/airflow,lyft/incubator-airflow,mrkm4ntr/incubator-airflow,mtagle/airflow