security: aa-helper: nvidia rules for gl devices

Further testing with different devices showed that we need more rules
to drive gl backends with nvidia cards. Related denies look like:

apparmor="DENIED" operation="open"
  name="/usr/share/egl/egl_external_platform.d/"
  requested_mask="r"
apparmor="DENIED" operation="open"
  name="/proc/modules"
  requested_mask="r"
apparmor="DENIED" operation="open"
  name="/proc/driver/nvidia/params"
  requested_mask="r"
apparmor="DENIED" operation="mknod"
  name="/dev/nvidiactl"
  requested_mask="c"

Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1817943Acked-by: NJamie Strandboge <jamie@canonical.com>
Signed-off-by: NChristian Ehrhardt <christian.ehrhardt@canonical.com>

src/security/virt-aa-helper.c

@@ -1279,6 +1279,11 @@ get_files(vahControl * ctl)
         virBufferAddLit(&buf, "  \"/usr/share/drirc.d/{,*.conf}\" r,\n");
         virBufferAddLit(&buf, "  \"/etc/glvnd/egl_vendor.d/{,*}\" r,\n");
         virBufferAddLit(&buf, "  \"/usr/share/glvnd/egl_vendor.d/{,*}\" r,\n");
+        virBufferAddLit(&buf, "  \"/usr/share/egl/egl_external_platform.d/\" r,\n");
+        virBufferAddLit(&buf, "  \"/usr/share/egl/egl_external_platform.d/*\" r,\n");
+        virBufferAddLit(&buf, "  \"/proc/modules\" r,\n");
+        virBufferAddLit(&buf, "  \"/proc/driver/nvidia/params\" r,\n");
+        virBufferAddLit(&buf, "  \"/dev/nvidiactl\" rw,\n");
         virBufferAddLit(&buf, "  # Probe DRI device attributes\n");
         virBufferAddLit(&buf, "  \"/dev/dri/\" r,\n");
         virBufferAddLit(&buf, "  \"/sys/devices/*/*/{uevent,vendor,device,subsystem_vendor,subsystem_device}\" r,\n");