sepolicy: Add write_logd, read_logd & control_logd

- Add write_logd, read_logd and control_logd macros added along
  with contexts for user space logd.
- Specify above on domain wide, or service-by-service basis
- Add logd rules.
- deprecate access_logcat as unused.
- 'allow <domain> zygote:unix_dgram_socket write;' rule added to
  deal with fd inheritance. ToDo: investigate means to allow
  references to close, and reopen in context of application
  or call setsockcreatecon() to label them in child context.

Change-Id: I35dbb9d5122c5ed9b8c8f128abf24a871d6b26d8
diff --git a/debuggerd.te b/debuggerd.te
index 0443aef..738dac2 100644
--- a/debuggerd.te
+++ b/debuggerd.te
@@ -23,3 +23,6 @@
 
 # Connect to system_server via /data/system/ndebugsocket.
 unix_socket_connect(debuggerd, system_ndebug, system_server)
+
+# logd access
+read_logd(debuggerd)