[sign_virt_apex] Update vbmeta related bootconfigs

Signing microdroid super images will change vbmeta digest & size, these
are embedded in ramdisk & hence need to be changed too. For this we
detach the bootconfigs from ramdisk, update them & re-attach them.

Other then that, this patch also removes signing of legacy images like
bootloader.

Test: atest
MicrodroidHostTests#testBootSucceedsWhenNonProtectedVmStartsWithImagesSignedWithDifferentKey
Bug: 245277660

Change-Id: Ia1d2ab0a7c76c7ee7435e55bab9a1c9d4f29f202
diff --git a/tests/hostside/Android.bp b/tests/hostside/Android.bp
index 7679c57..6e0cf5a 100644
--- a/tests/hostside/Android.bp
+++ b/tests/hostside/Android.bp
@@ -29,6 +29,7 @@
         // For re-sign test
         "avbtool",
         "img2simg",
+        "initrd_bootconfig",
         "lpmake",
         "lpunpack",
         "mk_payload",