Revert "tcp: restrict net.ipv4.tcp_app_win"

This reverts commit a069d4d9 which is
commit dc5110c2 upstream.

It breaks the Android kernel abi, and is not needed at this point in
time.  If it is required, it can come back in an ABI-safe way.

Bug: 161946584
Change-Id: I7ef145a192f15df2179150f9f0087746725d27ea
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>