docs/zh_CN: Add self-protection index Chinese translation

Translate .../security/self-protection.rst into Chinese.

Update the translation through commit b080e521
("docs: update self-protection __ro_after_init status")

Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Reviewed-by: Yuxian Mao <maoyuxian@cqsoftware.com.cn>
Signed-off-by: zhangwei <zhangwei@cqsoftware.com.cn>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/dd8c6da2e145aadac202e979bea0ff6b56431e0b.1738923258.git.zhangwei@cqsoftware.com.cn