They are not outsourced. These are tools assembled by Bosch employees in China.* The key parts are probably imported into China (to avoid having to pass on the relevant technology to the mandatory 50% Chinese partner) and bolted together there. A lot of final assembly is done in China because labor costs are so cheap that they outweigh the cost of shipping container-loads of different parts, sorting them out on the assembly line, and then shipping the assembled product back to stores on the other side of the planet.
* Who are probably better-educated than their counterparts in Germany, not because Chinese are generally better-educated, but because Bosch, like other Western companies, likely pays well above Chinese company wages to get a better-quality worker. This is what people mean when they talk about Chinese labor shortages. It's not a shortage of hands per se - it's a shortage of people qualified (ethically- and skill-wise) to work at Western companies at wages that are competitive with low-wage countries outside of China.