Initialize fs-verity keys in shell script

This gives us two benefits:
  - Better compatibility to keyctl(1), which doesn't have "dadd"
  - Pave the way to specify key's security labels, since keyctl(1)
    doesn't support, and we want to avoid adding incompatible option.

Test: See keys loaded in /proc/keys
Bug: 128607724
Change-Id: Ia45f6e9dea80d037c0820cf1fd2bc9d7c8bb6302
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 8e63a81..fec1e68 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -420,12 +420,7 @@
 
     # Load fsverity keys. This needs to happen before apexd, as post-install of
     # APEXes may rely on keys.
-    exec -- /system/bin/mini-keyctl dadd asymmetric product_cert /product/etc/security/cacerts_fsverity .fs-verity
-    exec -- /system/bin/mini-keyctl dadd asymmetric vendor_cert /vendor/etc/security/cacerts_fsverity .fs-verity
-    # Prevent future key links to fsverity keyring
-    exec -- /system/bin/mini-keyctl restrict_keyring .fs-verity
-    # Enforce fsverity signature checking
-    write /proc/sys/fs/verity/require_signatures 1
+    exec -- /system/bin/fsverity_init
 
     # Make sure that apexd is started in the default namespace
     enter_default_mount_ns