spec/ruby/library/socket/addrinfo/getnameinfo_spec.rb: skip on Android

FreeBSD's GETNAMEINFO(3) says:

> If a link-layer address or UNIX-domain address is passed to
> getnameinfo(), its ASCII representation will be stored in host.  The
> string pointed to by serv will be set to the empty string if non-NULL;
> flags will always be ignored.

Android seems to behave like FreeBSD.

spec/ruby/library/socket/addrinfo/getnameinfo_spec.rb

@@ -21,6 +21,7 @@ describe 'Addrinfo#getnameinfo' do
   end
 
   platform_is :linux do
+    platform_is_not :android do
       with_feature :unix_socket do
         describe 'using a UNIX Addrinfo' do
           before do
@@ -38,3 +39,4 @@ describe 'Addrinfo#getnameinfo' do
       end
     end
   end
+end