use new WindowCompat#enableEdgeToEdge API

Author: octocorvus

app/src/main/java/app/grapheneos/pdfviewer/PdfViewer.java

@@ -301,7 +301,7 @@ private void showWebViewCrashed() {
     @SuppressLint({"SetJavaScriptEnabled"})
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        WindowCompat.setDecorFitsSystemWindows(getWindow(), false);
+        WindowCompat.enableEdgeToEdge(getWindow());
 
         binding = PdfviewerBinding.inflate(getLayoutInflater());
         setContentView(binding.getRoot());