Set current state key earlier and do not reset hasCurrentState

- The current state key was updated to the new state key after the diff
calculations and base setting. There are a few cases where we exit the
current loop which results in the current state key not getting updated.
- When we reset the base, we should not reset the current state. All
instances where hasCurrentState was set to false have been removed.
- I added a unit test for a value metric that is sliced by state and has
a condition.

Bug: 157661456
Test: m statsd_test && adb sync data && adb shell
data/nativetest/statsd_test/statsd_test32

Change-Id: Ib75bd9d08e6785f9e03b4b5984dbdaf86a7e1749