IndexOutOfBoundsException observed in ProcessStats

Sometime, IndexOutOfBoundsException is observed in ProcessStats
while allocating longs array. This could be due to synchronization.
This fix will return if array index is >= size.

Change-Id: Icd81d84607ca28c5f1b0f9a05e255037252239fd
CRs-Fixed: 638977
Merge "IndexOutOfBoundsException observed in ProcessStats" into kitkat3