Reason for revert: Fix downstream. Original issue's description: > Revert of Allow custom metrics implementations on Android. (patchset #11 id:260001 of https://codereview.webrtc.org/2403463002/ ) > > Reason for revert: > Break downstream tests. > > Original issue's description: > > Allow custom metrics implementations on Android. > > > > BUG=webrtc:6499 > > > > Committed: https://crrev.com/de609b26c5fc77fd3388eae5594ee8a634edf8da > > Cr-Commit-Position: refs/heads/master@{#15169} > > TBR=kjellander@webrtc.org,magjed@webrtc.org,sakal@webrtc.org > # Skipping CQ checks because original CL landed less than 1 days ago. > NOPRESUBMIT=true > NOTREECHECKS=true > NOTRY=true > BUG=webrtc:6499 > > Committed: https://crrev.com/f570a2804ed8af6f6586f4aea51e089bd55d7e42 > Cr-Commit-Position: refs/heads/master@{#15171} TBR=kjellander@webrtc.org,magjed@webrtc.org,philipel@webrtc.org BUG=webrtc:6499 Review-Url: https://codereview.webrtc.org/2518293002 Cr-Commit-Position: refs/heads/master@{#15214}