Explicitly label logd's dependencies in /proc.

labeled /proc/kmsg as proc_kmsg, changed logd's access from proc to
proc_kmsg, and added a compat mapping.

Bug: 65643247
Test: device boots without selinux denials to the newly introduced proc_kmsg
Test: logd-unit-tests passes

Merged-In: I92c9f5694289eb6a94c4d90f14e2de4d46b5228e
Change-Id: I92c9f5694289eb6a94c4d90f14e2de4d46b5228e
(partial CP of commit 528da6fe3a0dbe4ae15355dff0152ab5f55197da)
diff --git a/private/genfs_contexts b/private/genfs_contexts
index 3914cec..9f6ef5d 100644
--- a/private/genfs_contexts
+++ b/private/genfs_contexts
@@ -5,6 +5,7 @@
 genfscon proc /config.gz u:object_r:config_gz:s0
 genfscon proc /interrupts u:object_r:proc_interrupts:s0
 genfscon proc /iomem u:object_r:proc_iomem:s0
+genfscon proc /kmsg u:object_r:proc_kmsg:s0
 genfscon proc /meminfo u:object_r:proc_meminfo:s0
 genfscon proc /misc u:object_r:proc_misc:s0
 genfscon proc /modules u:object_r:proc_modules:s0