function extractPublicEncryptionKey(replayDemInfo) {
    const matchInfo = cstrike15_gcmessages_1.CDataGCCStrike15V2MatchInfo.decode(replayDemInfo);
    return decodeEncryptionKey(matchInfo.watchablematchinfo.clDecryptdataKeyPub);
}
Extracts the public encryption key from a matchmaking demo.
The return value of this function can be passed into `DemoFile#setEncryptionKey`.
@param replayDemInfo Raw byte contents of the `match730_*.dem.info` file.