Revert^2 "Boot VM without bootloader - using init ramdisk"

Remove ABL from the boot flow of VMs. Virtualization service uses
microdroid.json to construct the appropriate vm_config.

Partitions:
1. Boot related partitions (boot/init_boot/vendor_boot) are no more
   required. kernel & init ramdisk is directly passed via crosvm command
   line.
2. uboot_env is obsolete without ABL
3. bootconfig partition is no more required because we are attaching the
   bootconfigs to initrd image.

This reverts commit 0f71596bd5333f08d07ed33dbb5425390dd8aa79

Bug: 240235424
Test: atest MicrodroidTestCase
Change-Id: I1b4c3ec792db9898093c4ccd3c037657c50a934f
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index 3b75df9..b35f8da 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -632,7 +632,7 @@
     vm_config.numCpus = config.numCpus;
     vm_config.taskProfiles = config.taskProfiles.clone();
 
-    // Microdroid requires an additional payload disk image and the bootconfig partition.
+    // Microdroid requires an additional init ramdisk & payload disk image
     if os_name == "microdroid" {
         add_microdroid_images(
             config,