Log the correct oom_adj when compacting apps.

The useful oom_adj value for app compaction logging is the
previous score, not the upcoming score. We were logging the wrong
value.

Test: verified through event log that values in logs look right.
Bug: 128682578
Change-Id: I7f9554802dac7b4f47579869adb851bc06239ba6
diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index 3246d19..b8e8fdc 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -4913,7 +4913,7 @@
   // since boot, not including sleep (see SystemClock.uptimeMillis()).
   optional int64 last_compact_timestamp_ms_since_boot = 14;
 
-  // The oom_score_adj at the time of compaction.
+  // The "setAdj" (i.e. previous) oom_score_adj at the time of compaction.
   optional int32 oom_score_adj = 15;
 
   // The process state at the time of compaction.