Build CaptivePortalLoginTests with both ABIs

Add compile_multilib "both" to the test so that it can be run with
both ABIs. This is necessary for test suites such as MTS.

Bug: 213536276
Change-Id: I5ce83b657715f252b131687eb6fffc8f94a71116
Test: m
diff --git a/tests/Android.bp b/tests/Android.bp
index 5550e26..1e5966b 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -23,6 +23,7 @@
     defaults: ["framework-connectivity-test-defaults"],
     srcs: ["src/**/*.java", "src/**/*.kt"],
     platform_apis: true,
+    compile_multilib: "both",
     min_sdk_version: "29",
     target_sdk_version: "31", // Keep in sync with CaptivePortalLogin
     test_suites: ["general-tests", "mts-networking"],