Clarified the WebChannel.getLastStatusCode() API.
Clarified the WebChannel.getLastStatusCode() API.

RELNOTES: none
PiperOrigin-RevId: 431783488
Change-Id: I0abbaf9c20b9f89c6ff7f75aec03663f3a714b68

google/closure-library,google/closure-library,google/closure-library,google/closure-library,google/closure-library