Android Studio's XML editor does a pretty good job of preserving padding based on @dimen...can we avoid using alignParentLeft on the overall layout?

```
 android:paddingLeft="@dimen/activity_horizontal_margin"
                android:paddingRight="@dimen/activity_horizontal_margin"
                android:paddingTop="@dimen/activity_vertical_margin"
                android:paddingBottom="@dimen/activity_vertical_margin"
```