BEIJING (Reuters) -Apple Inc achieved its highest-ever market share in China in the fourth quarter, when it was the top-selling vendor there for the first time in six years, research firm Counterpoint Research reported on Wednesday. The milestone coincided with the release of the iPhone 13, and amid otherwise stagnant demand for handsets as chief rival Huawei Technologies Co Ltd’s [HWT.UL] market share declined. Apple’s smartphone market share reached 23%, a record for the brand. Its unit sales volume grew 32% year-on-year in the quarter, while total smartphone sales in China fell 9%, according to Counterpoint. Counterpoint analyst Mengmeng Zhang...