Fix compiler warning about assignment in conditional.
Fix compiler warning about assignment in conditional.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140332890

superbderrick/ExoPlayer,google/ExoPlayer,fanhattan/ExoPlayer,androidx/media,zhouweiguo2017/ExoPlayer,rubensousa/exoplayer-amazon-port,rubensousa/exoplayer-amazon-port,JasonFengHot/ExoPlayerSource,ebr11/ExoPlayer,google/ExoPlayer,jcable/ExoPlayer,michalliu/ExoPlayer,YouKim/ExoPlayer,JasonFengHot/ExoPlayerSource,yangwuan55/ExoPlayer,MaTriXy/ExoPlayer,jcable/ExoPlayer,barbarian/ExoPlayer,saki4510t/ExoPlayer,superbderrick/ExoPlayer,michalliu/ExoPlayer,stari4ek/ExoPlayer,amzn/exoplayer-amazon-port,jeoliva/ExoPlayer,saki4510t/ExoPlayer,superbderrick/ExoPlayer,tntcrowd/ExoPlayer,fanhattan/ExoPlayer,ened/ExoPlayer,yangwuan55/ExoPlayer,KiminRyu/ExoPlayer,barbarian/ExoPlayer,zhouweiguo2017/ExoPlayer,tntcrowd/ExoPlayer,KiminRyu/ExoPlayer,androidx/media,barbarian/ExoPlayer,saki4510t/ExoPlayer,jcable/ExoPlayer,stari4ek/ExoPlayer,amzn/exoplayer-amazon-port,jeoliva/ExoPlayer,MaTriXy/ExoPlayer,yangwuan55/ExoPlayer,amzn/exoplayer-amazon-port,kiall/ExoPlayer,fanhattan/ExoPlayer,michalliu/ExoPlayer,google/ExoPlayer,stari4ek/ExoPlayer,zhouweiguo2017/ExoPlayer,YouKim/ExoPlayer,ebr11/ExoPlayer,WeiChungChang/ExoPlayer,androidx/media,YouKim/ExoPlayer,ened/ExoPlayer,kiall/ExoPlayer,ened/ExoPlayer,jeoliva/ExoPlayer,WeiChungChang/ExoPlayer,JasonFengHot/ExoPlayerSource,YouKim/ExoPlayer,tntcrowd/ExoPlayer,MaTriXy/ExoPlayer,ebr11/ExoPlayer,rubensousa/exoplayer-amazon-port,kiall/ExoPlayer,KiminRyu/ExoPlayer,WeiChungChang/ExoPlayer