Fix About AlertDialog colour/theme

Setting `parent="Theme.StrokeInput"` also has the bonus effect
of inflating the AlertDialog to full screen. Yay!

Author: yawnoc

CHANGELOG.md

@@ -4,6 +4,7 @@
 ## [Unreleased]
 
 - Made app main activity theme dark
+- Made `about.html` show full screen
 
 
 ## [v0.5.1] Visual improvements (2021-07-13)

app/src/main/java/io/github/yawnoc/strokeinput/MainActivity.java

@@ -57,7 +57,7 @@ else if (viewId == R.id.about_button) {
       final WebView htmlWebView = new WebView(this);
       htmlWebView.loadUrl(ABOUT_URI);
       final AlertDialog.Builder htmlAlertDialogBuilder =
-        new AlertDialog.Builder(this);
+        new AlertDialog.Builder(this, R.style.StrokeInputAlert);
       htmlAlertDialogBuilder
         .setView(htmlWebView)
         .setPositiveButton(R.string.activity_main_return_label, null)

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

@@ -20,6 +20,9 @@
     <item name="android:orientation">horizontal</item>
     <item name="android:gravity">center</item>
   </style>
+  <style name="StrokeInputAlert" parent="Theme.StrokeInput">
+    <item name="android:windowBackground">@color/very_dark_grey</item>
+  </style>
   <style name="StrokeInputText" parent="android:Widget.EditText">
     <item name="android:textColor">?android:textColor</item>
   </style>