allow dumpstate to collect ro.boottime.*

- necessary for analyzing early boot stage

bug: 35949319
Test: check captured bugreport for ro.boottime.* in SYSTEM PROPERTIES
Change-Id: I8826abd19ac00f169841b4a7ceeb68be3405d1b9

private/dumpstate.te

@@ -17,3 +17,6 @@ allow dumpstate storaged_exec:file rx_file_perms;
 
 # Allow dumpstate to make binder calls to storaged service
 binder_call(dumpstate, storaged)
+
+# Collect metrics on boot time created by init
+get_prop(dumpstate, boottime_prop)