Add Apache 2.0 license id lines to source files#543

jafingerhut wants to merge 4 commits intop4lang:mainp4lang/p4runtime:mainfrom

jafingerhut:add-apache-2.0-license-id-lines-to-source-filesjafingerhut/p4runtime:add-apache-2.0-license-id-lines-to-source-filesCopy head branch name to clipboard