Fix wallpaper restore

Following a restore of the wallpaper data files, the settingsRestored()
method was binding the new wallpaper by passing null as the component,
because once upon a time that meant just use the configuration that had
just been loaded from the [newly restored] settings filed.  However, at
some point this broke when the load from settings was made a staging
operation, not also the commitment of the changes.

This CL passes the newly-determined component configuration explicitly
to the bind, overriding the product default that may already have been
emplaced by the time the restore happens.

It also turns off the (minor) debugging that had been enabled in
WallpaperBackupHelper while digging into the issue.

Bug 5416839

Change-Id: I963893c236e24c75d10dde75836805295ea42cbb

services/java/com/android/server/WallpaperManagerService.java

@@ -834,7 +834,7 @@ class WallpaperManagerService extends IWallpaperManager.Stub {
                 }
                 if (DEBUG) Slog.v(TAG, "settingsRestored: success=" + success);
                 if (success) {
-                    bindWallpaperComponentLocked(null, false, false);
+                    bindWallpaperComponentLocked(mNextWallpaperComponent, false, false);
                 }
             }
         }