Add microdroid specific sepolicy

Microdroid will have a separate sepolicy, apart from the core policy.
This is the first step; For now it's a simple copy of system/sepolicy.
For the future work, it will be stripped.

Bug: 189165759
Test: boot microdroid and see selinux enforced
Change-Id: I2fee39f7231560b49c93bd5e8d0feeffada40938
diff --git a/microdroid/sepolicy/system/private/bootstat.te b/microdroid/sepolicy/system/private/bootstat.te
new file mode 100644
index 0000000..016292e
--- /dev/null
+++ b/microdroid/sepolicy/system/private/bootstat.te
@@ -0,0 +1,34 @@
+typeattribute bootstat coredomain;
+
+init_daemon_domain(bootstat)
+
+# Collect metrics on boot time created by init
+get_prop(bootstat, boottime_prop)
+
+# Read/Write [persist.]sys.boot.reason and ro.boot.bootreason (write if empty)
+set_prop(bootstat, bootloader_boot_reason_prop)
+set_prop(bootstat, system_boot_reason_prop)
+set_prop(bootstat, last_boot_reason_prop)
+
+neverallow {
+  domain
+  -bootanim
+  -bootstat
+  -dumpstate
+  userdebug_or_eng(`-incidentd')
+  -init
+  -recovery
+  -shell
+  -system_server
+} { bootloader_boot_reason_prop last_boot_reason_prop }:file r_file_perms;
+# ... and refine, as these components should not set the last boot reason
+neverallow { bootanim recovery } last_boot_reason_prop:file r_file_perms;
+
+neverallow {
+  domain
+  -bootstat
+  -init
+  -system_server
+} { bootloader_boot_reason_prop last_boot_reason_prop }:property_service set;
+# ... and refine ... for a ro propertly no less ... keep this _tight_
+neverallow system_server bootloader_boot_reason_prop:property_service set;