Add incidentcompanion service.

It is a side channel for dumpstate and incidentd to communicate
status and get user authorization to share bugreports by calling
system_server.

Test: atest PermissionControllerTest / atest GooglePermissionControllerTest
Change-Id: I995a43a25f375e5c97dba1deb92ebe893ca8585d
diff --git a/private/dumpstate.te b/private/dumpstate.te
index 606e510..e33d510 100644
--- a/private/dumpstate.te
+++ b/private/dumpstate.te
@@ -46,3 +46,6 @@
 dontaudit dumpstate perfprofd:binder call;
 dontaudit dumpstate update_engine:binder call;
 allow dumpstate proc_net_tcp_udp:file r_file_perms;
+
+# For comminucating with the system process to do confirmation ui.
+binder_call(dumpstate, incidentcompanion_service)