Fix edge-to-edge behaviour for portrait WebView alerts

NOTE: WebView alerts are still broken in landscape mode.
Is this a bug with how `fitsSystemWindows` is implemented
for `AlertDialog`?

Author: yawnoc

app/src/main/res/values/styles.xml

@@ -48,6 +48,7 @@
     <item name="android:padding">@dimen/padding__dialog_button</item>
   </style>
   <style name="StrokeInputAlert" parent="Theme.StrokeInput">
+    <item name="android:fitsSystemWindows">true</item>
     <item name="android:windowBackground">@color/very_dark_grey</item>
     <item name="android:backgroundDimEnabled">true</item>
   </style>