### What would you like to be added?

`net.ipv4.tcp_rmem` and `net.ipv4.tcp_wmem` have been namespaced since https://github.com/torvalds/linux/commit/356d1833b638bd465672aefeb71def3ab93fc17d (Linux Kernal Version >= 4.15)

It would be helpful to allow config these sysctls for each Pod(Application).




### Why is this needed?


The good performance of some applications depends on these sysctls, for example https://docs.datastax.com/en/cassandra-oss/3.x/cassandra/install/installRecommendSettings.html#TCPsettings.

To handle thousands of concurrent connections used by Cassandra, DataStax recommends these settings to optimize the Linux network stack. We should config these sysctls as the following:
```sh
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
```
It would be helpful to be able to configure this for applications without needing to modify the kubelet args.

Add net.ipv4.tcp_rmem and net.ipv4.tcp_wmem into safe sysctl list
This is a GitHub Issue
repo:kubernetes
owner:kubernetes
Title : Add net.ipv4.tcp_rmem and net.ipv4.tcp_wmem into safe sysctl list
Issue date:

--- start body ---
### What would you like to be added?

`net.ipv4.tcp_rmem` and `net.ipv4.tcp_wmem` have been namespaced since https://github.com/torvalds/linux/commit/356d1833b638bd465672aefeb71def3ab93fc17d (Linux Kernal Version >= 4.15)

It would be helpful to allow config these sysctls for each Pod(Application).




### Why is this needed?


The good performance of some applications depends on these sysctls, for example https://docs.datastax.com/en/cassandra-oss/3.x/cassandra/install/installRecommendSettings.html#TCPsettings.

To handle thousands of concurrent connections used by Cassandra, DataStax recommends these settings to optimize the Linux network stack. We should config these sysctls as the following:
```sh
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
```
It would be helpful to be able to configure this for applications without needing to modify the kubelet args.

--- end body ---
