Delete unused NetEq stats currentPacketLossRate, currentDiscardRate and addedSamples

Bug: webrtc:11622
Change-Id: I097bb7284d952ada41f4f38dd7adf3536bd040ee
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/183620
Reviewed-by: Minyue Li <minyue@google.com>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32148}
diff --git a/modules/audio_coding/neteq/neteq_unittest.proto b/modules/audio_coding/neteq/neteq_unittest.proto
index 344dcf6..b4b4253 100644
--- a/modules/audio_coding/neteq/neteq_unittest.proto
+++ b/modules/audio_coding/neteq/neteq_unittest.proto
@@ -7,8 +7,8 @@
   optional uint32 current_buffer_size_ms = 1;
   optional uint32 preferred_buffer_size_ms = 2;
   optional uint32 jitter_peaks_found = 3;
-  optional uint32 packet_loss_rate = 4;
-  optional uint32 packet_discard_rate = 5 [deprecated = true];
+  reserved 4;  // Was packet_loss_rate.
+  reserved 5;  // Was packet_discard_rate.
   optional uint32 expand_rate = 6;
   optional uint32 speech_expand_rate = 7;
   optional uint32 preemptive_rate = 8;
@@ -16,7 +16,7 @@
   optional uint32 secondary_decoded_rate = 10;
   optional uint32 secondary_discarded_rate = 17;
   optional int32 clockdrift_ppm = 11;
-  optional uint64 added_zero_samples = 12;
+  reserved 12;  // Was added_zero_samples.
   optional int32 mean_waiting_time_ms = 13;
   optional int32 median_waiting_time_ms = 14;
   optional int32 min_waiting_time_ms = 15;
@@ -29,4 +29,3 @@
   optional uint32 extended_max_sequence_number = 3;
   optional uint32 jitter = 4;
 }
-