Add the 'bdev_type' attribute to all block devices

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.
Change-Id: I959bae6f9590b1867905d46e194c45b0ea4248df
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/microdroid/system/public/attributes b/microdroid/system/public/attributes
index cf516dd..ffc2b3b 100644
--- a/microdroid/system/public/attributes
+++ b/microdroid/system/public/attributes
@@ -7,6 +7,9 @@
 # in tools/checkfc.c
 attribute dev_type;
 
+# Attribute for block devices.
+attribute bdev_type;
+
 # All types used for processes.
 attribute domain;
 
diff --git a/microdroid/system/public/device.te b/microdroid/system/public/device.te
index 8d286a6..bdc3b28 100644
--- a/microdroid/system/public/device.te
+++ b/microdroid/system/public/device.te
@@ -1,7 +1,7 @@
 type ashmem_device, dev_type, mlstrustedobject;
 type ashmem_libcutils_device, dev_type, mlstrustedobject;
 type binder_device, dev_type, mlstrustedobject;
-type block_device, dev_type;
+type block_device, dev_type, bdev_type;
 type console_device, dev_type;
 type device, dev_type, fs_type;
 type dm_device, dev_type;