Add -pkvm_experimental to the microdroid_gki_android14-6.1 artifacts

Current name suggests that android14-6.1 GKI can be run as guest, which
is not true. Resolve this confusion by explicitly specifying
-pkvm_experimental to the name, which points out that this image was
built from the android14-6.1-pkvm_experimental branch.

Bug: 329383978
Test: AVF presubmit
Test: vm run-microdroid --gki android14-6.1-pkvm_experimental
Change-Id: I0b93e0aacb9dde58c9a3c696d5a073e1800ec325
diff --git a/apex/Android.bp b/apex/Android.bp
index e6c809c..dfb979e 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -172,10 +172,10 @@
         },
         release_avf_enable_vendor_modules: {
             prebuilts: [
-                "microdroid_gki-android14-6.1_initrd_debuggable",
-                "microdroid_gki-android14-6.1_initrd_normal",
-                "microdroid_gki-android14-6.1_kernel",
-                "microdroid_gki-android14-6.1.json",
+                "microdroid_gki-android14-6.1-pkvm_experimental_initrd_debuggable",
+                "microdroid_gki-android14-6.1-pkvm_experimental_initrd_normal",
+                "microdroid_gki-android14-6.1-pkvm_experimental_kernel",
+                "microdroid_gki-android14-6.1-pkvm_experimental.json",
             ],
         },
         release_avf_enable_remote_attestation: {