Update test: true to mode: "test" in java_aconfig_library

Test: CI

Bug: 309990433

Merged-In: I630782e0280be8687d55b5878da1a253c0f0be1a
Change-Id: Ie72d65557d7522481802852b341d9b0f49b508a3

AconfigFlags.bp

@@ -149,7 +149,7 @@ java_aconfig_library {
     name: "android.security.flags-aconfig-java-host",
     aconfig_declarations: "android.security.flags-aconfig",
     host_supported: true,
-    test: true,
+    mode: "test",
     defaults: ["framework-minus-apex-aconfig-java-defaults"],
 }