For #15320: Ensure Mimetype Other PDF Shows PDF Icon

app/src/main/java/org/mozilla/fenix/ext/DownloadItem.kt

@@ -14,6 +14,7 @@ fun DownloadItem.getIcon(): Int {
         return when {
             fileName?.endsWith("apk") == true -> R.drawable.ic_file_type_apk
             fileName?.endsWith("zip") == true -> R.drawable.ic_file_type_zip
+            fileName?.endsWith("pdf") == true -> R.drawable.ic_file_type_document
             else -> R.drawable.ic_file_type_default
         }
     }

app/src/test/java/org/mozilla/fenix/ext/DownloadItemKtTest.kt

@@ -23,6 +23,7 @@ class DownloadItemKtTest {
         assertEquals(R.drawable.ic_file_type_zip, downloadItem.copy(contentType = "application/gzip").getIcon())
         assertEquals(R.drawable.ic_file_type_apk, downloadItem.copy(contentType = null, fileName = "Fenix.apk").getIcon())
         assertEquals(R.drawable.ic_file_type_zip, downloadItem.copy(contentType = null, fileName = "Fenix.zip").getIcon())
+        assertEquals(R.drawable.ic_file_type_document, downloadItem.copy(contentType = null, fileName = "Fenix.pdf").getIcon())
         assertEquals(R.drawable.ic_file_type_default, downloadItem.copy(contentType = null, fileName = null).getIcon())
     }
 }