logd: logpersistd

- Enable logpersistd to write to /data/misc/logd
- Enable logpersistd to read from pstore to help complete any content
  lost by reboot disruption
- Enable shell readonly ability logpersistd files in /data/misc/logd
- Enable logcat -f when placed into logd context to act as a
  logpersistd (nee logcatd) agent, restrict access to run only in
  userdebug or eng

Bug: 19608716
Change-Id: I3209582bc796a1093c325c90068a48bf268e5ab5
diff --git a/file_contexts b/file_contexts
index cc152f6..5ca2852 100644
--- a/file_contexts
+++ b/file_contexts
@@ -236,6 +236,7 @@
 /data/misc/gatekeeper(/.*)?     u:object_r:gatekeeper_data_file:s0
 /data/misc/keychain(/.*)?       u:object_r:keychain_data_file:s0
 /data/misc/keystore(/.*)?       u:object_r:keystore_data_file:s0
+/data/misc/logd(/.*)?           u:object_r:misc_logd_file:s0
 /data/misc/media(/.*)?          u:object_r:media_data_file:s0
 /data/misc/net(/.*)?            u:object_r:net_data_file:s0
 /data/misc/shared_relro(/.*)?   u:object_r:shared_relro_file:s0