[avb_footer] Include initrd_* hashes as hash descriptors in kernel footer

This cl also removes the old initrd_* digests included as prop of kernel
hash descriptor.
The new footer will have 3 hash descriptors for kernel, initrd_normal
and initrd_debug.

This is the reland of the change aosp/2375868. The build of initrd on
linux-x86 that has incorrect format (b/264940248) is disabled in this
cl.

Bug: 260821553
Test: m microdroid_kernel_signed and inspect the output using `avbtool
info_image --image <output>`

Change-Id: I401e476f34dcd0ae0dd07e50d8fe19e3f2533d9a
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index ecaadf8..b46f112 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -538,6 +538,46 @@
     srcs: ["bootconfig.normal"],
 }
 
+// python -c "import hashlib; print(hashlib.sha256(b'initrd_normal').hexdigest())"
+initrd_normal_salt = "8041a07d54ac82290f6d90bac1fa8d7fdbc4db974d101d60faf294749d1ebaf8"
+
+avb_gen_vbmeta_image {
+    name: "microdroid_initrd_normal_hashdesc",
+    src: ":microdroid_initrd_normal",
+    partition_name: "vbmeta_initrd_normal",
+    salt: initrd_normal_salt,
+    enabled: false,
+    arch: {
+        // Microdroid kernel is only available in these architectures.
+        arm64: {
+            enabled: true,
+        },
+        x86_64: {
+            enabled: true,
+        },
+    },
+}
+
+// python -c "import hashlib; print(hashlib.sha256(b'initrd_debug').hexdigest())"
+initrd_debug_salt = "8ab9dc9cb7e6456700ff6ef18c6b4c3acc24c5fa5381b829563f8d7a415d869a"
+
+avb_gen_vbmeta_image {
+    name: "microdroid_initrd_debug_hashdesc",
+    src: ":microdroid_initrd_debuggable",
+    partition_name: "vbmeta_initrd_debug",
+    salt: initrd_debug_salt,
+    enabled: false,
+    arch: {
+        // Microdroid kernel is only available in these architectures.
+        arm64: {
+            enabled: true,
+        },
+        x86_64: {
+            enabled: true,
+        },
+    },
+}
+
 avb_add_hash_footer {
     name: "microdroid_kernel_signed",
     src: "empty_kernel",
@@ -556,11 +596,9 @@
             enabled: true,
         },
     },
-    props: [
-        {
-            name: "trusted_ramdisk",
-            file: ":microdroid_initrd_hashes",
-        },
+    include_descriptors_from_images: [
+        ":microdroid_initrd_normal_hashdesc",
+        ":microdroid_initrd_debug_hashdesc",
     ],
 }