examples: enable option to auto clear I2S tx descriptor on underflow

Closes: https://github.com/espressif/esp-idf/issues/1945

examples/bluetooth/a2dp_gatts_coex/main/main.c

@@ -650,8 +650,9 @@ void app_main()
         .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,                           //2-channels
         .communication_format = I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB,
         .dma_buf_count = 6,
-        .dma_buf_len = 60,                                                      //
-        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1                                //Interrupt level 1
+        .dma_buf_len = 60,
+        .intr_alloc_flags = 0,                                                  //Default interrupt priority
+        .tx_desc_auto_clear = true                                              //Auto clear tx descriptor on underflow
     };
 
 

examples/bluetooth/a2dp_sink/main/main.c

@@ -63,8 +63,9 @@ void app_main()
         .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,                           //2-channels
         .communication_format = I2S_COMM_FORMAT_I2S_MSB,
         .dma_buf_count = 6,
-        .dma_buf_len = 60,                                                      //
-        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1                                //Interrupt level 1
+        .dma_buf_len = 60,
+        .intr_alloc_flags = 0,                                                  //Default interrupt priority
+        .tx_desc_auto_clear = true                                              //Auto clear tx descriptor on underflow
     };