media: update media_codecs_performance.xml

Update metric for OMX.qcom.video.encoder.hevc 3840x2160

Bug: 31337886
Change-Id: Iee54010323181deef0ca49e52d7ee9dec87d358b
(cherry picked from commit 69d081efca3100489efa446ce3c6c887e833c796)
1 file changed