Mark neteq_rtpplay as publicly visible.

Bug: None
Change-Id: I051c7c23851ab15345c8e0f0322458d4f9a7e187
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128123
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27162}

modules/audio_coding/BUILD.gn

@@ -1457,6 +1457,7 @@ if (rtc_include_tests) {
 
     rtc_test("neteq_rtpplay") {
       testonly = true
+      visibility += [ "*" ]
       defines = []
       deps = [
         ":neteq_test_factory",