[YouTube] Add missing prettyPrint query parameter to some test InnerTube requests

This query parameter for which its value is set to false was not added to two
requests made in test classes of YoutubeMixPlaylistExtractorTest.

Also remove an unneeded ParsingException exception throwing declaration in a
test method.

Author: AudricV

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeMixPlaylistExtractorTest.java

@@ -22,7 +22,6 @@
 import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
-import org.schabi.newpipe.extractor.playlist.PlaylistExtractor;
 import org.schabi.newpipe.extractor.playlist.PlaylistInfo;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeMixPlaylistExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
@@ -454,7 +453,8 @@ void getPage() throws Exception {
                     .getBytes(StandardCharsets.UTF_8);
 
             final InfoItemsPage<StreamInfoItem> streams = extractor.getPage(new Page(
-                    YOUTUBEI_V1_URL + "next?key=" + getKey(), null, null, dummyCookie, body));
+                    YOUTUBEI_V1_URL + "next?key=" + getKey() + DISABLE_PRETTY_PRINT_PARAMETER,
+                    null, null, dummyCookie, body));
             assertFalse(streams.getItems().isEmpty());
             assertTrue(streams.hasNextPage());
         }
@@ -542,7 +542,8 @@ void getPage() throws Exception {
                     .getBytes(StandardCharsets.UTF_8);
 
             final InfoItemsPage<StreamInfoItem> streams = extractor.getPage(new Page(
-                    YOUTUBEI_V1_URL + "next?key=" + getKey(), null, null, dummyCookie, body));
+                    YOUTUBEI_V1_URL + "next?key=" + getKey() + DISABLE_PRETTY_PRINT_PARAMETER,
+                    null, null, dummyCookie, body));
             assertFalse(streams.getItems().isEmpty());
             assertTrue(streams.hasNextPage());
         }
@@ -570,7 +571,7 @@ void getContinuations() throws Exception {
         }
 
         @Test
-        void getStreamCount() throws ParsingException {
+        void getStreamCount() {
             assertEquals(ListExtractor.ITEM_COUNT_INFINITE, extractor.getStreamCount());
         }