Fix to reduce memory usage of gapis video.
Fix to reduce memory usage of gapis video.

It no longer grows with each image.

Qining/gapid,google/agi,google/gapid,Qining/gapid,google/gapid,pmuetschard/gapid,google/agi,pmuetschard/gapid,pmuetschard/gapid,Qining/gapid,google/agi,google/gapid,google/agi,pmuetschard/gapid,Qining/gapid,pmuetschard/gapid,pmuetschard/gapid,Qining/gapid,google/agi,google/gapid,google/agi,google/gapid,pmuetschard/gapid,google/gapid,google/gapid,pmuetschard/gapid,Qining/gapid,Qining/gapid,google/agi,google/gapid,Qining/gapid,google/agi