The last used shared media period is reused after all media periods have been
released. In case the sample streams are already filled up, they need to be
reset or they download samples from the current position up to the seek
position. This causes long buffering states or load stuck exceptions.
A seek when reusing the shared period takes care for reseting the period or
internally seeks to the current position in the already available samples.
#minor-release
PiperOrigin-RevId: 428484187
28b8ae7076