Implement review suggestions

Author: gzsombor

app/src/main/java/free/rm/skytube/businessobjects/opml/OpmlParser.java

@@ -23,7 +23,6 @@
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Matcher;
@@ -213,6 +212,7 @@ private static String tryExtractChannelId(String url, Pattern primaryPattern, Pa
      * @throws XmlPullParserException If there's an error parsing the XML
      */
     public static List<ParsedChannel> parseOpml(String opmlString) throws IOException, XmlPullParserException {
+        // Using "UTF-8" is intentional, so we can keep the same code in SkytubeLegacy too.
         try (InputStream inputStream = new ByteArrayInputStream(opmlString.getBytes("UTF-8"))) {
             return parseOpml(inputStream);
         }

app/src/main/res/values/strings_subs.xml

@@ -25,7 +25,7 @@
 	<string name="select_all">Select All</string>
 	<string name="select_none">Select None</string>
 	<string name="no_channels_found">Could not find any YouTube channels in the file you uploaded.</string>
-	<string name="no_new_channels_found">We couldn\'t find any YouTube channels that you don\'t already subscribed.</string>
+	<string name="no_new_channels_found">We couldn\'t find any YouTube channels that you aren\'t already subscribed to.</string>
 	<string name="import_subscriptions_parse_error">Could not parse the file you uploaded: %s.</string>
 	<string name="failed_to_import_subscriptions">Could not import your YouTube subscriptions.</string>
 

app/src/test/java/free/rm/skytube/businessobjects/opml/OpmlParserTest.java

@@ -165,36 +165,6 @@ void testAllOpmlFilesParseWithoutErrors() throws Exception {
         }
     }
 
-    @Test
-    void testOpmlFileExtensionDetection() {
-        // Test that .opml files are correctly identified
-        String[] opmlFiles = {
-            "subscriptions.opml",
-            "export.OPML",  // Case insensitive
-            "backup.opml",
-            "test.opml.xml" // Should still be detected as OPML first
-        };
-
-        String[] nonOpmlFiles = {
-            "subscriptions.xml",
-            "export.json",
-            "backup.txt",
-            "subscriptions.opml.backup" // Doesn't end with .opml
-        };
-
-        for (String filename : opmlFiles) {
-            if (filename.toLowerCase().endsWith(".opml")) {
-                assertTrue(filename.toLowerCase().endsWith(".opml"),
-                          filename + " should be detected as OPML");
-            }
-        }
-
-        for (String filename : nonOpmlFiles) {
-            assertFalse(filename.toLowerCase().endsWith(".opml"),
-                       filename + " should NOT be detected as OPML");
-        }
-    }
-
     @Test
     void testOpmlStructureConsistency() throws Exception {
         // Test that all OPML files have consistent structure