Add back platform APIs to HostsideNetworkTestsApp

The "platform_apis: true" clause was removed by mistake and is actually
necessary.

Ignore-AOSP-First: original change not in AOSP
Fixes: 184844380
Test: atest HostsideVpnTests
Change-Id: I32bd4a7057a3eb167975fe9f51f1bc0d056c44a0
diff --git a/tests/cts/hostside/app/Android.bp b/tests/cts/hostside/app/Android.bp
index 9dd86de..1e35a61 100644
--- a/tests/cts/hostside/app/Android.bp
+++ b/tests/cts/hostside/app/Android.bp
@@ -24,6 +24,7 @@
         "cts_support_defaults",
         "framework-connectivity-test-defaults",
     ],
+    platform_apis: true,
     static_libs: [
         "androidx.test.rules",
         "androidx.test.ext.junit",