Steam Deck OS Preview Update: Two Small Fixes

Note: This update is for the Steam Deck Preview channel, and includes new features that are still being tested. You can opt into this in Settings > System > Steam Update Channel.

• Fixed Chinese Pinyin and Zhuyin input for the on-screen keyboard not functioning correctly
  
• Added a workaround for an underlying Steam/Proton issue causing some games -- notably Vampire Survivors -- to fail to launch