Generate Java host library for keystore2 flags

This will be used by the host side test/EDI collector.

Bug: 369210366
Test: build and use the flag on the host side
Change-Id: I01354a77cd91d2a417219b308862a6903ecaa404
diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index f50c052..88b674e 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -175,6 +175,12 @@
     aconfig_declarations: "keystore2_flags",
 }
 
+java_aconfig_library {
+    name: "keystore2_flags_java-host",
+    aconfig_declarations: "keystore2_flags",
+    host_supported: true,
+}
+
 rust_aconfig_library {
     name: "libkeystore2_flags_rust",
     crate_name: "keystore2_flags",