Allow dumpstate to call idmap over binder

This prevents denials while taking a bugreport.

Bug: 116711254
Test: cts-tradefed run cts -m CtsSecurityHostTestCases -t
android.security.cts.SELinuxHostTest#testNoBugreportDenials

Change-Id: I5414141a1557d71e3ac0cf5bc89529685e9069c3

private/dumpstate.te

@@ -34,6 +34,9 @@ binder_call(dumpstate, statsd)
 # Allow dumpstate to talk to gpuservice over binder
 binder_call(dumpstate, gpuservice);
 
+# Allow dumpstate to talk to idmap over binder
+binder_call(dumpstate, idmap);
+
 # Collect metrics on boot time created by init
 get_prop(dumpstate, boottime_prop)