Pass all scans to battery stats

Also let battery stats know if the scan that was just stopped
was optimized or not.

Bug: 63456783
Test: runtest -x frameworks/base/core/tests/coretests/src/com/android/internal/os/BatteryStatsTests.java
Change-Id: Ic8308cdfe8654a7628fd6181dde9898483f528aa
Merged-In: Ic8308cdfe8654a7628fd6181dde9898483f528aa
(cherry picked from commit 824d8f2f)