Add the visibility of net-utils-framework-common for cts-net

DnsResolverTest required DnsPacket to parse DNS answer, and the
DnsPacket class is provided by system previously.
However, DnsPacket was moved to here with changed package,
which has no backward-compatibility and might cause
NoClassDefFoundError. To solve this problem, build the DnsResolverTest with
DnsPacket directly.

Test: build
Test: atest DnsResolverTest
Bug: 150952393
Change-Id: I463fd58173cee55a210fa6c6b8c9b0d5a74b7906
diff --git a/common/Android.bp b/common/Android.bp
index d93579b..0f8dda0 100644
--- a/common/Android.bp
+++ b/common/Android.bp
@@ -45,6 +45,7 @@
     sdk_version: "system_current",
     jarjar_rules: "jarjar-rules-shared.txt",
     visibility: [
+        "//cts/tests/tests/net",