Adjust SB license and content test triggers (#41831)

Co-authored-by: Matt Thalman <[email protected]>

Author: MichaelSimons

src/SourceBuild/content/eng/pipelines/source-build-sdk-diff-tests.yml

@@ -11,10 +11,13 @@ resources:
   pipelines:
   - pipeline: dotnet-source-build
     source: dotnet-source-build
+    # For releases branches only run on internal/release branches because that's where dependencies flow.
+
+    # Previews don't have internal/release branches so they must be run from non-internal release branches.
     trigger:
       branches:
         include:
-          - refs/heads/release/*.0.1xx*
+          - refs/heads/release/*.0.1xx-preview*
           - refs/heads/internal/release/*.0.1xx*
 
 pr: none

src/SourceBuild/content/eng/pipelines/vmr-license-scan.yml

@@ -4,9 +4,11 @@ schedules:
 - cron: "0 7 * * 1"
   displayName: Run on Mondays at 7am UTC
   branches:
+    # For releases branches only run on internal/release branches because that's where dependencies flow.
+    # Previews don't have internal/release branches so they must be run from non-internal release branches.
     include:
     - main
-    - release/*.0.1xx*
+    - release/*.0.1xx-preview*
     - internal/release/*.0.1xx*
 
 pr: none
@@ -16,7 +18,7 @@ trigger:
   branches:
     include:
     - main
-    - release/*.0.1xx*
+    - release/*.0.1xx-preview*
     - internal/release/*.0.1xx*
   paths:
     include: