This CL fixes a bug that CursorAnchorInfoBuilder does't make a copy if the Matrix specified with #setMatrix. Without this fix, IMM#updateCursorAnchorInfo could fail to detect duplicated events when the same instances of CursorAnchorInfoBuilder and Matrix are reused to optimize performance. Change-Id: I50c50a12a06d3cda4dec445b171b61ceb78da21a