HBASE-12199 Make TestAtomicOperation and TestEncodedSeekers faster

Signed-off-by: Elliott Clark <eclark@apache.org>
Revert "HBASE-12148 Remove TimeRangeTracker as point of contention when many threads writing a Store"

This reverts commit 9f2e748f0a33a5b939a3768c8aeb10432ad43b23.

Post commit consensus is this change isn't ready yet.
Fix failures caused by Jacoco syncthetic methods

Signed-off-by: Andrew Purtell <apurtell@apache.org>