Fix Duck Player not loading in Android 8. Fixes #5148 (#5156)

Task/Issue URL:
https://app.asana.com/0/414730916066338/1208567891699607/f

### Description
Fixes #5148
Looks like there's a bug in MimeTypeMap on Android that causes it to
return null for JS files in some Android versions, which prevents Duck
Player from loading. Added a fallback for such cases

### Steps to test this PR

_Feature 1_
- [x] Install app in a device running Android 8
- [x] If app crashes on startup due to an old webview, follow
instructions here https://app.asana.com/0/0/1208589697450045/f
- [x] Search for a YouTube video
- [x] Open in Duck Player
- [x] Check Duck Player loads and is functional

duckplayer/duckplayer-impl/src/main/java/com/duckduckgo/duckplayer/impl/RealDuckPlayer.kt

@@ -308,7 +308,7 @@ class RealDuckPlayer @Inject constructor(
         webView: WebView,
     ): WebResourceResponse {
         val path = getDuckPlayerAssetsPath(url)
-        val mimeType = mimeTypeMap.getMimeTypeFromExtension(path?.substringAfterLast("."))
+        val mimeType = getMimeTypeFromExtension(path?.substringAfterLast("."))
 
         if (path != null && mimeType != null) {
             try {
@@ -336,6 +336,16 @@ class RealDuckPlayer @Inject constructor(
         }
     }
 
+    private fun getMimeTypeFromExtension(extension: String?): String? {
+        return mimeTypeMap.getMimeTypeFromExtension(extension) ?: when (extension) {
+            "css" -> "text/css"
+            "html" -> "text/html"
+            "js" -> "application/javascript"
+            "jpg" -> "image/jpeg"
+            else -> null
+        }
+    }
+
     private suspend fun processYouTubeWatchUri(
         request: WebResourceRequest,
         url: Uri,