fix(accessibility): android:textColorHint

android:textColorHint was #79747E. On #E4F5FD this led to a contrast of 4.07:1

#716C76 is 4.57:1 - acceptable for text

Assisted-by: Claude Opus 4.7 - color

Author: david-allison

AnkiDroid/src/main/res/values/theme_light.xml

@@ -7,6 +7,7 @@
         <item name="colorPrimaryDark">@color/material_light_blue_700</item>
         <item name="colorSurface">@color/white</item>
         <item name="colorOnSurface">@color/black</item>
+        <item name="android:textColorHint">#716C76</item>
         <item name="colorAccent">@color/material_blue_grey_700</item>
         <item name="colorPrimaryContainer">@color/white</item> <!-- Switch thumb color when disabled and being pressed -->
         <item name="colorOnPrimaryContainer">@color/white</item> <!-- FAB icons -->