by updating flag that T1 frame can be referenced when it is encoded
rather than when it is sent for encoding.
Otherwise when encoder drops T1 frame, configuration for following T2 frame would
still try to reference that absent T1 frame leading to invalid references.
Bug: None
Change-Id: I6398275971596b0618bcf9c926f0282f74120976
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/202030
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33002}