Refactor bottom app bar native ad layout

The layout for the bottom app bar native ad was refactored to:
- Use a LinearLayout as the root container instead of MaterialCardView.
- Adjust padding and margins for better visual appearance.
- Set a minimum width and height for the ad call-to-action button.
- Change the ad container height in `activity_main.xml` to `wrap_content`.

Author: MihaiCristianCondrea

app/src/main/res/layout/activity_main.xml

@@ -44,7 +44,7 @@
     <FrameLayout
         android:id="@+id/ad_container"
         android:layout_width="match_parent"
-        android:layout_height="50dp"
+        android:layout_height="wrap_content"
         app:layout_constraintBottom_toTopOf="@+id/nav_view">
 
         <View

app/src/main/res/layout/bottom_app_bar_native_ad.xml

@@ -1,31 +1,26 @@
 <?xml version="1.0" encoding="utf-8"?>
 <com.google.android.gms.ads.nativead.NativeAdView xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="wrap_content">
 
-    <com.google.android.material.card.MaterialCardView
-        android:id="@+id/ad_card"
-        style="@style/Widget.Material3.CardView.Outlined"
+    <LinearLayout
+        android:id="@+id/ad_host"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:layout_marginHorizontal="16dp"
-        app:shapeAppearanceOverlay="@style/ShapeAppearanceOverlay.CardViewTopRounded">
+        android:orientation="vertical"
+        android:background="?attr/colorSurfaceContainer"
+        android:paddingStart="16dp"
+        android:paddingEnd="16dp"
+        android:paddingTop="12dp"
+        android:paddingBottom="12dp">
 
-        <include
-            layout="@layout/ad_attribution"
-            android:layout_gravity="top|start"
-            android:layout_margin="8dp" />
+        <include layout="@layout/ad_attribution" />
 
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:orientation="horizontal"
             android:gravity="center_vertical"
-            android:paddingStart="16dp"
-            android:paddingEnd="16dp"
-            android:paddingTop="24dp"
-            android:paddingBottom="8dp">
+            android:orientation="horizontal">
 
             <ImageView
                 android:id="@+id/ad_app_icon"
@@ -61,7 +56,9 @@
                 style="@style/Widget.Material3.Button.TextButton"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
+                android:minWidth="64dp"
+                android:minHeight="36dp"
                 android:layout_marginStart="8dp" />
         </LinearLayout>
-    </com.google.android.material.card.MaterialCardView>
+    </LinearLayout>
 </com.google.android.gms.ads.nativead.NativeAdView>