Batterystats BLE results counter takes in count

There would likely be too many BLE scan result calls for batterystats to
be healthy. Therefore, the caller can supply a count by which to increase the
counter, instead of doing it one result at a time.

Bug: 37720787
Test: runtest -x frameworks/base/core/tests/coretests/src/com/android/internal/os/BatteryStatsTests.java
Change-Id: Ib8b2e8d250036be24c6c3dac477bc8d34fe498a6