Merge changes from topics "move-kerneltotag", "move-socket-tagging-to-mainline"

* changes:
  Move socket tagging implementation to mainline.
  Move kernelToTag to NetworkStatsFactory.

service-t/src/com/android/server/net/NetworkStatsFactory.java

@@ -22,8 +22,6 @@ import static android.net.NetworkStats.TAG_ALL;
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 
-import static com.android.server.NetworkManagementSocketTagger.kernelToTag;
-
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
@@ -469,6 +467,19 @@ public class NetworkStatsFactory {
         }
     }
 
+    /**
+     * Convert {@code /proc/} tag format to {@link Integer}. Assumes incoming
+     * format like {@code 0x7fffffff00000000}.
+     */
+    public static int kernelToTag(String string) {
+        int length = string.length();
+        if (length > 10) {
+            return Long.decode(string.substring(0, length - 8)).intValue();
+        } else {
+            return 0;
+        }
+    }
+
     /**
      * Parse statistics from file into given {@link NetworkStats} object. Values
      * are expected to monotonically increase since device boot.