Use Mat3 menu and dialog in Media Preview toolbar/save.

app/src/main/java/org/thoughtcrime/securesms/MediaPreviewActivity.java

@@ -51,6 +51,8 @@ import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 import androidx.viewpager.widget.ViewPager;
 
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+
 import org.signal.core.util.logging.Log;
 import org.thoughtcrime.securesms.animation.DepthPageTransformer;
 import org.thoughtcrime.securesms.attachments.DatabaseAttachment;
@@ -84,8 +86,6 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 
-import io.reactivex.rxjava3.subjects.BehaviorSubject;
-
 /**
  * Activity for displaying media attachments in-app
  */
@@ -466,7 +466,7 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
       return;
     }
 
-    AlertDialog.Builder builder = new AlertDialog.Builder(this);
+    AlertDialog.Builder builder = new MaterialAlertDialogBuilder(this);
     builder.setIcon(R.drawable.ic_warning);
     builder.setTitle(R.string.MediaPreviewActivity_media_delete_confirmation_title);
     builder.setMessage(R.string.MediaPreviewActivity_media_delete_confirmation_message);

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

@@ -80,6 +80,7 @@
 
         <androidx.appcompat.widget.Toolbar
             android:id="@+id/toolbar"
+            android:theme="?actionBarStyle"
             android:layout_width="match_parent"
             android:layout_height="?attr/actionBarSize"
             android:background="@android:color/transparent" />