Follow-up to rename system to system_server.

1fdee11d renamed domain system to
system_server in AOSP. This CL applies the rename to the rules that
weren't in AOSP at the time.

Change-Id: I0e226ddca2e01ed577204ddb4886a71f032a01ed

zygote.te

@@ -49,5 +49,5 @@ allow zygote zygote_exec:file { execute_no_trans open };
 allow zygote ashmem_device:chr_file execute;
 allow zygote init:binder call;
 allow zygote shell_data_file:file { write getattr };
-allow zygote system:binder { transfer call };
+allow zygote system_server:binder { transfer call };
 allow zygote servicemanager:binder { call };