Flac extension: disable BinarySearchSeeker if totalSamples is unknown

The ceilingTimePosition is based on the total number of samples. Binary
search seeking is not possible if this value is unknown.

PiperOrigin-RevId: 292921177

extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/FlacExtractor.java

@@ -250,7 +250,7 @@ public final class FlacExtractor implements Extractor {
     SeekMap seekMap;
     if (haveSeekTable) {
       seekMap = new FlacSeekMap(streamMetadata.getDurationUs(), decoderJni);
-    } else if (streamLength != C.LENGTH_UNSET) {
+    } else if (streamLength != C.LENGTH_UNSET && streamMetadata.totalSamples > 0) {
       long firstFramePosition = decoderJni.getDecodePosition();
       binarySearchSeeker =
           new FlacBinarySearchSeeker(