Stop setting swappiness.

We're re-enabling memory cgroups on Ariel
to use user-space lmkd. As a side-effect, this
code will start setting swappiness again. Since the
benefit of swappiness is unknown at this point
(see b/18248535 for details), disable it until
we have good data it helps.

Change-Id: I8e8b892ba0db27469f2d47615f71ce1d2712acbf
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index b4d2746..466d7bc 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -18707,8 +18707,6 @@
                         }
                     }
                 }
-                Process.setSwappiness(app.pid,
-                        app.curSchedGroup <= Process.THREAD_GROUP_BG_NONINTERACTIVE);
             }
         }
         if (app.repForegroundActivities != app.foregroundActivities) {