Currently, Java equivalent of webrtc::field_trial::FindFullName is in PeeerConnectionFactory, which belongs to peerconnection_java GN target. Move that method into a separate file and GN target to make it easier to use the fieldTrialsFindFullName method in other code. Bug: webrtc:13973 Change-Id: I4d7d30339883af76c1d066f72270c6caf9c64c49 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/261500 Reviewed-by: Xavier Lepaul <xalep@webrtc.org> Commit-Queue: Xavier Lepaul <xalep@webrtc.org> Cr-Commit-Position: refs/heads/main@{#37233}