[microdroid] Rename the partition name of microdroid_kernel to boot

Bug: 262853105
Test: atest libpvmfw_avb.test
Change-Id: Ic0d1f6b2c1023337a5fa2b8251fb40d80e162f37
diff --git a/microdroid/Android.bp b/microdroid/Android.bp
index c62db2d..1fc44a2 100644
--- a/microdroid/Android.bp
+++ b/microdroid/Android.bp
@@ -582,7 +582,7 @@
     name: "microdroid_kernel_signed",
     src: "empty_kernel",
     filename: "microdroid_kernel",
-    partition_name: "bootloader",
+    partition_name: "boot",
     private_key: ":microdroid_sign_key",
     salt: bootloader_salt,
     enabled: false,