android:lineSpacingMultiplier doesn't work in android:textAppearance

For whatever reason android:lineSpacingMultiplier doesn't work as an item within your textAppearance. You'll either have to set it directly as a TextView attribute (using android:lineSpacingMultiplier), or create a regular style which "wraps" setting the textAppearance and lineSpacingMultiplier

Create a style

<style name="TextBody1">
    <item name="android:textAppearance">@style/TextAppearance.AppCompat.Body1</item>
    <item name="android:lineSpacingMultiplier">1.25</item>
</style>

or

<style name="TextBody1" parent="TextAppearance.AppCompat.Body1">
    <item name="android:lineSpacingMultiplier">1.25</item>
</style>

and then apply via style instead of android:textAppearance

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="This is body 1\nThis is body 1"
    style="@style/TextBody1"
    />