Support linkerconfig in Runtime APEX

Add additional sepolicy so linkerconfig in Runtime APEX can be executed
from init.

Bug: 165769179
Test: Cuttlefish boot succeeded
Change-Id: Ic08157ce4c6a084db29f427cf9f5ad2cb12e50dd
diff --git a/apex/com.android.runtime-file_contexts b/apex/com.android.runtime-file_contexts
index eed0981..d090d50 100644
--- a/apex/com.android.runtime-file_contexts
+++ b/apex/com.android.runtime-file_contexts
@@ -4,4 +4,5 @@
 (/.*)?                   u:object_r:system_file:s0
 /bin/crash_dump(32|64)   u:object_r:crash_dump_exec:s0
 /bin/linker(64)?         u:object_r:system_linker_exec:s0
+/bin/linkerconfig        u:object_r:linkerconfig_exec:s0
 /lib(64)?(/.*)?          u:object_r:system_lib_file:s0