Ensure line-break after last attribute.

[JakeWharton]

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

becomes

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    />

which is much better for diffs and moving attributes up/down.

@edenman

[edenman]

[johnjohndoe]

One thought: One could argue that ...

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

</LinearLayout>

... is even better since it allows adding child nodes.

[JakeWharton]

The > should still be on a newline in that case, which this PR enforces.

[johnjohndoe]

Yes:

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

</LinearLayout>