Update apex_available for libapkverify and libapkzip

- Adds "//apex_available:platform" to the "apex_available" property of
  each library

Bug: 270617194
Test: Add "libapkverify" as a dependency to a binary
Test: m
Change-Id: I01efb4aa01d404a45961dcc6ae2d9c505f96fdb3
diff --git a/libs/apkverify/Android.bp b/libs/apkverify/Android.bp
index 4c5a622..90de043 100644
--- a/libs/apkverify/Android.bp
+++ b/libs/apkverify/Android.bp
@@ -27,7 +27,10 @@
     defaults: ["libapkverify.defaults"],
     // TODO(b/204562227): move to host_supported to the defaults to include tests
     host_supported: true,
-    apex_available: ["com.android.virt"],
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.virt",
+    ],
 }
 
 rust_test {