message: Add Emma Zhu as code owner
diff: /sdk/keyvault/ @vhvb1989 @gearama @antkmsft @rickwinter
  # PRLabel: %Storage
  -/sdk/storage/ @vinjiang @katmsft @Jinming-Hu @antkmsft @vhvb1989 @gearama @LarryOsterman
  +/sdk/storage/ @vinjiang @katmsft @Jinming-Hu @EmmaZhu @antkmsft @vhvb1989 @gearama @LarryOsterman
  # PRLabel: %EngSys
  /sdk/template/ @danieljurek @weshaggard
  