Add gid=3009,hidepid=2 options to the /proc mount.

This change is to allow the following CTS test to pass:

CtsOsTestCases android.os.cts.EnvironmentTest#testHidePid2

Bug: b/120611589
Test: Assured the emulator would boot.  Checked kernel logs for
problems.  Did adb shell and checked /proc/mounts for correctness.  Ran
CTS test to assert that it passes.

Change-Id: I936a22a30a65499832279021c3aeb89268612df9
diff --git a/init.ranchu.rc b/init.ranchu.rc
index 0c11d9b..b318b0d 100644
--- a/init.ranchu.rc
+++ b/init.ranchu.rc
@@ -3,6 +3,7 @@
 
 on early-init
     mount debugfs debugfs /sys/kernel/debug mode=755
+    mount proc proc /proc remount hidepid=2,gid=3009
 
 on init
 
diff --git a/sepolicy/common/init.te b/sepolicy/common/init.te
index 84a4e8d..9c01f79 100644
--- a/sepolicy/common/init.te
+++ b/sepolicy/common/init.te
@@ -1,2 +1,3 @@
 allow init tmpfs:lnk_file create_file_perms;
+allow init proc:dir { mounton };
 dontaudit init kernel:system module_request;