Batterystats track background bad ble scan time

Allows tracking ble scan time (total and background) for unoptimized
scans. Whether the scan is unoptimized is provided by the bluetooth
code when calling batterystats.

Bug: 38461344
Test: runtest -x frameworks/base/core/tests/coretests/src/com/android/internal/os/BatteryStatsTests.java
Test: run cts-dev -m CtsIncidentHostTestCases -t com.android.server.cts.BatteryStatsValidationTest#testUnoptimizedBleScans
Test: cts-tradefed run cts-dev -m CtsDumpsysHostTestCases -t android.dumpsys.cts.BatteryStatsDumpsysTest

Change-Id: I814482ff663424170eac4b413464d24c14a5cf91