ProcessStats: fix uss average value offset

Test: make framework -j8

Change-Id: If8f9c46293bb36fbbd2ebde5eace2d45cc6d4a12
Signed-off-by: ShuJie Wang <wangshujie@xiaomi.com>

core/java/com/android/internal/app/procstats/PssTable.java

@@ -96,7 +96,7 @@ public class PssTable extends SparseMappingTable.Table {
             }
 
             val = getValue(key, PSS_USS_AVERAGE);
-            setValue(key, PSS_AVERAGE,
+            setValue(key, PSS_USS_AVERAGE,
                     (long)(((val*(double)count)+(avgUss*(double)inCount)) / (count+inCount)));
 
             val = getValue(key, PSS_USS_MAXIMUM);