BatteryStats: Add WorkChain support for WiFi events.

The changes are straightforward, the only change outside of BatteryStats
is to use the new WorkSource.isEmpty API to account for WorkChains in a
given WorkSource.

Bug: 62390666
Test: BatteryStatsBackgroundStatsTest, BatteryStatsNoteTest, WifiLockManagerTest
Change-Id: I1dff43b6f2a09877e3af4442bfe8a8fd80b1ba74
diff --git a/framework/java/android/bluetooth/le/BluetoothLeScanner.java b/framework/java/android/bluetooth/le/BluetoothLeScanner.java
index a189e27..347fc4d 100644
--- a/framework/java/android/bluetooth/le/BluetoothLeScanner.java
+++ b/framework/java/android/bluetooth/le/BluetoothLeScanner.java
@@ -387,7 +387,7 @@
                 if (mScannerId > 0) {
                     mLeScanClients.put(mScanCallback, this);
                 } else {
-                    // Registration timed out or got exception, reset scannerId to -1 so no
+                    // Registration timed out or got exception, reset RscannerId to -1 so no
                     // subsequent operations can proceed.
                     if (mScannerId == 0) mScannerId = -1;