Allow microdroid_manager to set dev.bootcomplete

... and shell to get the same property for testing.

Bug: 230774156
Test: atest MicrodroidTestCase
Change-Id: Iaf04072c2b394d44ef1253fd048d5ccf757a8b89
diff --git a/microdroid/system/private/shell.te b/microdroid/system/private/shell.te
index c93b488..d6c3c0d 100644
--- a/microdroid/system/private/shell.te
+++ b/microdroid/system/private/shell.te
@@ -35,6 +35,7 @@
 dontaudit shell sysfs:dir r_dir_perms;
 
 # Test tool tries to read various service status properties.
+get_prop(shell, boot_status_prop)
 get_prop(shell, init_service_status_prop)
 get_prop(shell, init_service_status_private_prop)