Convert vintf_fragments into vintf_fragment module(s)

Convert vintf_fragments into vintf_fragment module(s) so those manifests
can be handled in the same way between KATI defined system image and
Soong defined system image.

Bug: 322089980
Test: aosp_cf_x86_64_phone build succeeded
Change-Id: I25a30ef2b2baa01d9e15cd1b586eed17ac0d4a1f
diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index 7bba687..f50c052 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -123,6 +123,11 @@
     require_root: true,
 }
 
+vintf_fragment {
+    name: "android.system.keystore2-service.xml",
+    src: "android.system.keystore2-service.xml",
+}
+
 rust_defaults {
     name: "keystore2_defaults",
     srcs: ["src/keystore2_main.rs"],
@@ -141,7 +146,7 @@
     // selection available in the build system.
     prefer_rlib: true,
 
-    vintf_fragments: ["android.system.keystore2-service.xml"],
+    vintf_fragment_modules: ["android.system.keystore2-service.xml"],
 
     required: ["keystore_cli_v2"],
 }