android.sdk aconfig flags: add android.sdk.flags-aconfig-java-host

Add a new soong host module for the android.sdk aconfig flags. This
module will be used by CTS host tests.

Bug: 377689343
Test: treehugger
Flag: EXEMPT no need to flag changes to flags themselves
Change-Id: I8d1e0c39ab4c9129ed0238ba1ccf08fa29f6efd1

Author: amhk

android-sdk-flags/Android.bp

@@ -28,3 +28,10 @@ java_aconfig_library {
     aconfig_declarations: "android.sdk.flags-aconfig",
     defaults: ["framework-minus-apex-aconfig-java-defaults"],
 }
+
+java_aconfig_library {
+    name: "android.sdk.flags-aconfig-java-host",
+    aconfig_declarations: "android.sdk.flags-aconfig",
+    host_supported: true,
+    defaults: ["framework-minus-apex-aconfig-java-defaults"],
+}