bpf is required so /sys/fs/bpf/map_netd_app_uid_stats_map always exists

(we cannot just remove the argument, since the test code path still
 goes via the legacy xt_qtaguid code paths with sample data)

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I044d0363aaab0dbbb90c40ca466cc48f169d649a

services/core/java/com/android/server/net/NetworkStatsFactory.java

@@ -159,7 +159,7 @@ public class NetworkStatsFactory {
     }
 
     public NetworkStatsFactory() {
-        this(new File("/proc/"), new File("/sys/fs/bpf/map_netd_app_uid_stats_map").exists());
+        this(new File("/proc/"), true);
     }
 
     @VisibleForTesting