Add system_server system_file file to bug_map

The issue seems non-trivial, so I've added it to the bug map pending a
fix.

Bug: 291210768
Test: Null
Change-Id: I296c90f678f03083e68a44277bea7a74686fba08
diff --git a/shared/sepolicy/vendor/google/bug_map b/shared/sepolicy/vendor/google/bug_map
index 4b5b737..e227b5e 100644
--- a/shared/sepolicy/vendor/google/bug_map
+++ b/shared/sepolicy/vendor/google/bug_map
@@ -1,4 +1,5 @@
 untrusted_app selinuxfs file b/175910397
 zygote ramdump_app process b/139558100
 
+system_server system_file file b/291210768
 rs zygote fd b/291211299