Add dropped input buffers to DebugTextViewHelper

The field is more relevant with the
`experimentalSetLateThresholdToDropDecoderInputUs` API.

PiperOrigin-RevId: 726383978

Author: ychaparov

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/util/DebugTextViewHelper.java

@@ -182,6 +182,8 @@ private static String getDecoderCountersBufferCountString(DecoderCounters counte
         + counters.skippedOutputBufferCount
         + " rb:"
         + counters.renderedOutputBufferCount
+        + " dib:"
+        + counters.droppedInputBufferCount
         + " db:"
         + counters.droppedBufferCount
         + " mcdb:"