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/apex/com.android.virt-file_contexts b/apex/com.android.virt-file_contexts
index fe91fa2..4703eba 100644
--- a/apex/com.android.virt-file_contexts
+++ b/apex/com.android.virt-file_contexts
@@ -1,2 +1,3 @@
 (/.*)?                   u:object_r:system_file:s0
+/bin/crosvm              u:object_r:crosvm_exec:s0
 /bin/virtmanager         u:object_r:virtmanager_exec:s0