Add Yuchen to CODEOWNERS for Auth packages (#4144)

Author: sam-gc

.github/CODEOWNERS

@@ -55,8 +55,8 @@ packages/messaging-types @zwu52 @firebase/jssdk-global-approvers
 integration/messaging @zwu52 @firebase/jssdk-global-approvers
 
 # Auth Code
-packages/auth  @bojeil-google @avolkovi @samhorlbeck @firebase/jssdk-global-approvers
-packages/auth-types  @bojeil-google @avolkovi @samhorlbeck @firebase/jssdk-global-approvers
+packages/auth  @bojeil-google @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
+packages/auth-types  @bojeil-google @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
 
 # Testing Code
 packages/testing  @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
@@ -89,9 +89,9 @@ scripts/docgen/content-sources/ @firebase/firebase-techwriters @firebase/jssdk-g
 .changeset @firebase/firebase-techwriters @firebase/jssdk-changeset-approvers @firebase/firestore-js-team @firebase/jssdk-global-approvers
 
 # Auth-Exp Code
-packages-exp/auth-exp  @avolkovi @samhorlbeck @firebase/jssdk-global-approvers
-packages-exp/auth-types-exp  @avolkovi @samhorlbeck @firebase/jssdk-global-approvers
-packages-exp/auth-compat-exp @avolkovi @samhorlbeck @firebase/jssdk-global-approvers
+packages-exp/auth-exp  @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
+packages-exp/auth-types-exp  @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
+packages-exp/auth-compat-exp @avolkovi @samhorlbeck @yuchenshi @firebase/jssdk-global-approvers
 
 # Installations-Exp Code
 packages/installations-exp @andirayo @ChaoqunCHEN @firebase/jssdk-global-approvers