[PLAT-18584] YNP doesn't correctly handle vm.swappiness setting

Summary: If vm.swappiness is already set in sysctl.conf, we should replace the line in file (because it could have incorrect value)

Test Plan: provision instance with vm.swappiness=1 in cofigs

Reviewers: anijhawan, vkumar

Reviewed By: vkumar

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D46978

Author: yorq

managed/node-agent/resources/ynp/modules/provision/configure_os/templates/run.j2

@@ -51,8 +51,10 @@ ulimit -u {{ nproc_limit }}
 
 # Configure kernel settings
 # Set and persist vm.swappiness
-if ! grep -q "^vm.swappiness=" /etc/sysctl.conf; then
+if ! grep -q "^vm.swappiness" /etc/sysctl.conf; then
   echo "vm.swappiness={{ vm_swappiness }}" >> /etc/sysctl.conf
+else
+  sed -i "s/^vm.swappiness.*/vm.swappiness={{ vm_swappiness }}/" /etc/sysctl.conf
 fi
 sysctl -w vm.swappiness={{ vm_swappiness }}