ANDROID: revert "sysfs_net_ipv4: Add sysfs-based knobs for controlling TCP window size"

This reverts commit 41b377f5.

Q userspace no longer requires these tunables, and the 4.19 android common kernel
no longer carries this patch, so revert it also in 4.9 android common kernel.

Bug: 126767155
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ic1e71701b873f153ae067d15f675479eee249333