zygote/dex2oat: Grant additional symlink permissions

* zygote needs to be able to symlink from dalvik cache to system
  to avoid having to copy boot.oat
  (when the boot.oat file was built with --compile-pic)
* dex2oat needs to be able to read the symlink in the dalvik cache
  (the one that zygote creates)

(cherry-picked from AOSP master
83c5612e)

Bug: 18035729

(cherry picked from commit f7ccfd00)

Change-Id: I5dca27241f46f481515b96e968fb2bef7866c89b

dex2oat.te

@@ -3,6 +3,8 @@ type dex2oat, domain;
 type dex2oat_exec, exec_type, file_type;
 
 allow dex2oat dalvikcache_data_file:file write;
+# Read symlinks in /data/dalvik-cache
+allow dex2oat dalvikcache_data_file:lnk_file read;
 allow dex2oat installd:fd use;
 
 # Read already open asec_apk_file file descriptors passed by installd.

zygote.te

@@ -27,6 +27,8 @@ allow zygote keychain_data_file:file r_file_perms;
 # Write to /data/dalvik-cache.
 allow zygote dalvikcache_data_file:dir create_dir_perms;
 allow zygote dalvikcache_data_file:file create_file_perms;
+# Create symlinks in /data/dalvik-cache
+allow zygote dalvikcache_data_file:lnk_file create_file_perms;
 # Write to /data/resource-cache
 allow zygote resourcecache_data_file:dir rw_dir_perms;
 allow zygote resourcecache_data_file:file create_file_perms;