Prefetch: Add sepolicy to control prefetch properties

1: Add prefetch tunable property
2: Default path to store the prefetch record is in /metadata/prefetch/
3: Add policy to control the service
4: Allow init to start/stop the service

Bug: 362507272
Test: Test prefetch record/replay with enforcing mode
Change-Id: I55cbf4f2110da298a8d7df52daad08eaedebd061
Signed-off-by: Akilesh Kailash <akailash@google.com>
diff --git a/private/shell.te b/private/shell.te
index 70f296e..3b7a1f5 100644
--- a/private/shell.te
+++ b/private/shell.te
@@ -185,6 +185,8 @@
 # Allow shell to start/stop gsid via ctl.start|stop|restart gsid.
 set_prop(shell, ctl_gsid_prop)
 set_prop(shell, ctl_snapuserd_prop)
+# Allow shell to start/stop prefetch
+set_prop(shell, ctl_prefetch_prop)
 # Allow shell to enable Dynamic System Update
 set_prop(shell, dynamic_system_prop)
 # Allow shell to mock an OTA using persist.pm.mock-upgrade