Add the 'bdev_type' attribute to all block device types

The following patch iterates over all block devices:
https://android-review.googlesource.com/c/platform/system/core/+/1783847/9

The following patch grants 'init' and 'apexd' permission to iterate over
all block devices:
https://android-review.googlesource.com/c/platform/system/sepolicy/+/1783947

The above SELinux policy change requires to add the 'bdev_type'
attribute to all block devices. Hence this patch.

Bug: 194450129
Test: Untested.
Signed-off-by: Bart Van Assche <bvanassche@google.com>
Change-Id: Iee1c984f176eb2752194493999921cb1aa24ac64
diff --git a/microdroid/system/public/device.te b/microdroid/system/public/device.te
index bdc3b28..cc3519e 100644
--- a/microdroid/system/public/device.te
+++ b/microdroid/system/public/device.te
@@ -34,6 +34,6 @@
 type uhid_device, dev_type, mlstrustedobject;
 type uio_device, dev_type;
 type userdata_sysdev, dev_type;
-type vd_device, dev_type;
+type vd_device, dev_type, bdev_type;
 type vndbinder_device, dev_type;
 type zero_device, dev_type, mlstrustedobject;