Add log for anomaly.

This cl adds all the info that need to be logged to Anomaly and add a
dump method for log.

Bug: 63776178
Test: RunSettingsRoboTests
Change-Id: If762bfca725fee07944ffa23998332c81335a37f

src/com/android/settings/fuelgauge/anomaly/AnomalyLoader.java

@@ -25,8 +25,11 @@ import android.support.annotation.VisibleForTesting;
 import android.util.Log;
 
 import com.android.internal.os.BatteryStatsHelper;
+import com.android.internal.util.ArrayUtils;
 import com.android.settings.utils.AsyncLoader;
 
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;