They're not an arms exporter to Israel. Israel is the arms/military equipment/technology exporter to China in that relationship. Israel was trying for years to become China’s back door to western military technology and arms due to sanctions on China from the US and Europe that aimed to freeze China’s access to advanced military technology and weapons after the events at Tiananmen. China’s military exports are mostly to Pakistan, Bangladesh, and Algeria. They tend to prioritize selling weapons to their neighbors.
It’s a factor. The sale of Israeli military technology for developing tanks, air-to-air missiles, and jet fighters to China that helped modernize China’s army and air force frightened a lot of western government officials:
America has still been trying to limit Israel from re-exporting shared western military technology to China and did manage to force Israel to cancel some of their previous deals that included upgrading Chinese drones with their technology and the sale of their airborne early-warning radar system technology to China. Western officials are also still afraid of a civil-military integration strategy in China where the Chinese government encourages commercial exchange with the west to then funnel acquired technologies to China’s military. With many of the most advanced chips in the semiconductor industry being developed in Israel and the dual-use nature of semiconductors, American officials are concerned that China’s interest in this sector would be used to further modernize and strengthen the PLA, which has goals of completing military modernization by 2035 and of becoming a “world-class” military by 2049. There's also the issue where China likely does not want Israel right now to become another government to strengthen military ties with Taiwan (oddly enough, Israel was the first in the middle east to recognize the PRC as the legitimate government of China in 1950, which is something I still don't really understand why). China’s arms imports still overwhelmingly come from Russia.
Vietnam has also become one of Israel’s largest markets for weapons and surveillance technology. Regardless, it would still be best imo for socialist governments (including Vietnam and China) to adopt the DPRK’s approach to Israel: