External CI: change amd-master trigger to amd-mainline (#10)

[ROCm/roctracer commit: 9cca903417]

projects/roctracer/.azuredevops/rocm-ci.yml

@@ -13,7 +13,7 @@ trigger:
   batch: true
   branches:
     include:
-    - amd-master
+    - amd-mainline
     - amd-staging
   paths:
     exclude:
@@ -26,7 +26,7 @@ pr:
   autoCancel: true
   branches:
     include:
-    - amd-master
+    - amd-mainline
     - amd-staging
   paths:
     exclude: