cache RawTouch and dispatch during Input_Update#272

SiyaoHuang merged 1 commit intoprepare_2.0.6Unity-Technologies/com.unity.uiwidgets:prepare_2.0.6from

siyaoH/1.17/combineTouchUnity-Technologies/com.unity.uiwidgets:siyaoH/1.17/combineTouchCopy head branch name to clipboard