Add crosvm domain and give virtmanager and crosvm necessary permissions.

Bug: 183583115
Test: make TARGET_KERNEL_USE=5.4 TARGET_VIM3L=true
Change-Id: I566436fa2d27597566014f2a63198a88d6d2dbd6
diff --git a/private/file.te b/private/file.te
index 984a7b6..4d43c13 100644
--- a/private/file.te
+++ b/private/file.te
@@ -56,3 +56,6 @@
 
 # /data/system/environ
 type environ_system_data_file, file_type, data_file_type, core_data_file_type;
+
+# /dev/kvm
+type kvm_device, dev_type;