Update FlexFEC field trial string in AppRTCMobile Android.

BUG=webrtc:5654

Review-Url: https://codereview.webrtc.org/2847543004
Cr-Original-Commit-Position: refs/heads/master@{#17924}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 56c78aea5fad3f7a690ff2a3e3ddb5c49af05aa8
1 file changed