Remove process whitelist from memory measurements

The process whitelist can still be applied on the statsd configuration
layer. By removing the whitelist, we eliminate the memory measurement
blindspot.

10064 latency on 100 iterations:
  avg: 57ms
  max: 357ms

Bug: 148365709
Test: Manual
Change-Id: I6e826896b4c874bbb10ea2be65034d39dfff50a3