fix: Fix type passed to isTypeSupported in some cases (#7233)

Fixes #7232

On some Comcast devices (Flex series) calling `isTypeSupported()` with
base codec string results in video playback failure and an immediate
application crash.

lib/media/streaming_engine.js

@@ -1965,8 +1965,8 @@ shaka.media.StreamingEngine = class {
         reference.startTime <= appendWindowEnd,
         logPrefix + ' segment should start before append window end');
 
-    const codecs = MimeUtils.getCodecBase(
-        reference.codecs || mediaState.stream.codecs);
+    const fullCodecs = (reference.codecs || mediaState.stream.codecs);
+    const codecs = MimeUtils.getCodecBase(fullCodecs);
     const mimeType = MimeUtils.getBasicType(
         reference.mimeType || mediaState.stream.mimeType);
     const timestampOffset = reference.timestampOffset;
@@ -1984,7 +1984,7 @@ shaka.media.StreamingEngine = class {
       const isResetMediaSourceNecessary =
           mediaState.lastCodecs && mediaState.lastMimeType &&
           this.playerInterface_.mediaSourceEngine.isResetMediaSourceNecessary(
-              mediaState.type, mediaState.stream, mimeType, codecs);
+              mediaState.type, mediaState.stream, mimeType, fullCodecs);
       if (isResetMediaSourceNecessary) {
         let otherState = null;
         if (mediaState.type === ContentType.VIDEO) {