test: disable security manager for custom realm integration tests
test: disable security manager for custom realm integration tests

Original commit: elastic/x-pack-elasticsearch@4bcd7675b2d1f484ae0e9a1c04e0411eb0b234d3

strapdata/elassandra,uschindler/elasticsearch,gfyoung/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,HonzaKral/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,scorpionvicky/elasticsearch,robin13/elasticsearch,uschindler/elasticsearch,nknize/elasticsearch,vroyer/elassandra,strapdata/elassandra,coding0011/elasticsearch,gfyoung/elasticsearch,HonzaKral/elasticsearch,scorpionvicky/elasticsearch,uschindler/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,uschindler/elasticsearch,nknize/elasticsearch,gingerwizard/elasticsearch,coding0011/elasticsearch,scorpionvicky/elasticsearch,vroyer/elassandra,nknize/elasticsearch,strapdata/elassandra,scorpionvicky/elasticsearch,vroyer/elassandra,gingerwizard/elasticsearch,gfyoung/elasticsearch,strapdata/elassandra,uschindler/elasticsearch,GlenRSmith/elasticsearch,coding0011/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,coding0011/elasticsearch,gfyoung/elasticsearch,HonzaKral/elasticsearch,gfyoung/elasticsearch,gingerwizard/elasticsearch,nknize/elasticsearch,strapdata/elassandra,gingerwizard/elasticsearch,coding0011/elasticsearch,HonzaKral/elasticsearch