Adding some logging around launcher restore

> Also enabling fileLog when the device is debug build (even when
launcher is not dogfood build)

Bug: 30735662
Change-Id: Ieab2c962d57f6f7f972f8111070d4ecbef06b3e7
diff --git a/src/com/android/launcher3/LauncherBackupAgent.java b/src/com/android/launcher3/LauncherBackupAgent.java
index b3e73f7..140794b 100644
--- a/src/com/android/launcher3/LauncherBackupAgent.java
+++ b/src/com/android/launcher3/LauncherBackupAgent.java
@@ -5,11 +5,19 @@
 import android.app.backup.BackupDataOutput;
 import android.os.ParcelFileDescriptor;
 
+import com.android.launcher3.logging.FileLog;
 import com.android.launcher3.provider.RestoreDbTask;
 
 public class LauncherBackupAgent extends BackupAgent {
 
     @Override
+    public void onCreate() {
+        super.onCreate();
+        // Set the log dir as LauncherAppState is not initialized during restore.
+        FileLog.setDir(getFilesDir());
+    }
+
+    @Override
     public void onRestore(
             BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState) {
         // Doesn't do incremental backup/restore