style(new reviewer): make buttons 'Elevated'

the rest of the reviewer UI is elevated (WebView, type answer container)

also, it makes more evident that it is a button

and I think that it looks nicer, specially on big screens

Author: BrayanDSO

AnkiDroid/src/main/res/layout-sw600dp/reviewer2.xml

@@ -200,11 +200,13 @@
 
                 <com.google.android.material.button.MaterialButton
                     android:id="@+id/show_answer"
+                    style="@style/AnswerButton"
                     android:layout_width="match_parent"
                     android:layout_height="match_parent"
                     android:text="@string/show_answer"
                     android:textSize="@dimen/reviewer_answer_button_textSize"
                     app:cornerRadius="12dp"
+                    android:textColor="@color/white"
                     android:backgroundTint="?showAnswerButtonBackground"
                     tools:visibility="invisible"
                     />

AnkiDroid/src/main/res/layout/reviewer2.xml

@@ -202,11 +202,13 @@
 
             <com.google.android.material.button.MaterialButton
                 android:id="@+id/show_answer"
+                style="@style/AnswerButton"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:text="@string/show_answer"
                 android:textSize="@dimen/reviewer_answer_button_textSize"
                 app:cornerRadius="12dp"
+                android:textColor="@color/white"
                 android:backgroundTint="?showAnswerButtonBackground"
                 tools:visibility="invisible"
                 />

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

@@ -35,6 +35,8 @@
 
     <dimen name="reviewer_side_margin">8dp</dimen>
     <dimen name="answer_button_margin_horizontal">3dp</dimen>
+    <dimen name="study_screen_elevation">0.8dp</dimen>
+    <dimen name="answer_button_corner_radius">12dp</dimen>
     <dimen name="reviewer_answer_button_textSize">14sp</dimen>
     <dimen name="reviewer_mark_flag">18dp</dimen>
 </resources>

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

@@ -29,10 +29,11 @@
         <item name="android:popupBackground">@drawable/bg_popup</item>
     </style>
 
-    <style name="AnswerButton" parent="Widget.Material3.Button">
+    <style name="AnswerButton" parent="Widget.Material3.Button.ElevatedButton">
         <item name="android:padding">0dp</item>
-        <item name="cornerRadius">12dp</item>
+        <item name="cornerRadius">@dimen/answer_button_corner_radius</item>
         <item name="android:textSize">@dimen/reviewer_answer_button_textSize</item>
+        <item name="elevation">@dimen/study_screen_elevation</item>
     </style>
 
     <!--  Material Design-style persistent footer button -->
@@ -239,7 +240,7 @@
     </style>
 
     <style name="CardView.ViewerStyle" parent="Widget.Material3.CardView.Elevated">
-        <item name="android:elevation">0.8dp</item>
+        <item name="android:elevation">@dimen/study_screen_elevation</item>
     </style>
 
     <style name="Theme.AppCompat.Transparent.NoActionBar" parent="Theme.AppCompat.Light.DarkActionBar">