Enable build triggers after default branch rename from master to main (#4291)

azure-pipelines.yml

@@ -36,6 +36,7 @@ trigger:
   batch: true 
   branches:
     include: 
+    - main
     - release/3.*
     - release/5.*
     - internal/release/5.*
@@ -48,6 +49,7 @@ pr:
   autoCancel: true
   branches:
     include:
+    - main
     - release/3.* 
     - internal/release/3.*
     - release/5.*