Increased SHM size by mounting a volume

[mogaal]

This PR increases shared memory for Nginx ingress controller in order to fix an issue we're currently having in live-1:

"modsecurity_rules" directive Failed to allocate shared memory (1): No space left on device in /tmp/nginx-cfg337881831:12572

The problem is Kubernetes only provides 64MB for shared memory [1] which doesn't look enough for our nginx-ingress-controllers (they're getting bigger every day). Some other applications (like PostgreSQL) are also implementing similar approaches.

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[1] Easly checked as:

bash-5.0$ df -h | grep shm
shm                      64.0M         0     64.0M   0% /dev/shm
bash-5.0$