[test] Export avb_testkey_rsa8192 as filegroup for tests

Bug: 256148034
Test: atest libvbmeta_rust.test
Change-Id: Ia94161df500f2b43360d6a44b01dea562ca67193
diff --git a/test/Android.bp b/test/Android.bp
index 259b243..321e068 100644
--- a/test/Android.bp
+++ b/test/Android.bp
@@ -44,6 +44,11 @@
 }
 
 filegroup {
+    name: "avb_testkey_rsa8192",
+    srcs: ["data/testkey_rsa8192.pem"],
+}
+
+filegroup {
     name: "avb_testkey_rsa4096",
     srcs: ["data/testkey_rsa4096.pem"],
 }