Sort imports

Having consistent import order will reduce chance of merge
conflict between internal and external master

Test: rebuild
Change-Id: I0b1a170967ddcce7f388603fd521f6ed1eeba30b

src/com/android/settings/applications/assist/AssistSettingObserver.java

@@ -21,12 +21,12 @@ import android.database.ContentObserver;
 import android.net.Uri;
 import android.provider.Settings;
 
+import androidx.annotation.MainThread;
+
 import com.android.settingslib.utils.ThreadUtils;
 
 import java.util.List;
 
-import androidx.annotation.MainThread;
-
 public abstract class AssistSettingObserver extends ContentObserver {
 
     private final Uri ASSIST_URI =