Make MediaCodecRenderer.codec nullable

Also fix annotation style of the surrounding functions.

PiperOrigin-RevId: 288865420

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java

@@ -634,7 +634,8 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
    * method if they are taking over responsibility for output format propagation (e.g., when using
    * video tunneling).
    */
-  protected final @Nullable Format updateOutputFormatForTime(long presentationTimeUs) {
+  @Nullable
+  protected final Format updateOutputFormatForTime(long presentationTimeUs) {
     Format format = formatQueue.pollFloor(presentationTimeUs);
     if (format != null) {
       outputFormat = format;
@@ -642,11 +643,13 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
     return format;
   }
 
+  @Nullable
   protected final MediaCodec getCodec() {
     return codec;
   }
 
-  protected final @Nullable MediaCodecInfo getCodecInfo() {
+  @Nullable
+  protected final MediaCodecInfo getCodecInfo() {
     return codecInfo;
   }