Update Sbom.yml to add ability to allow disabling signing (#50)

* Update Sbom.yml to add ability to disable signing

* Fix environment variable name

Author: adityapatwardhan

Sbom.yml

@@ -13,6 +13,8 @@ parameters:
     default: '0.0.0'
   - name: sourceScanPath
     default: $(Build.SourcesDirectory)
+  - name: signSBOM
+    default: true
 
 steps:
 - task: UseDotNet@2
@@ -52,6 +54,7 @@ steps:
     BuildComponentPath: ${{ parameters.sourceScanPath }}
   env:
     SBOMGenerator_Formats: '${{ parameters.SBOMGenerator_Formats }}'
+    PACKAGING_ENABLESBOMSIGNING: '${{ parameters.signSBOM }}'
     # *** Leaving these as documentation of the rest of the inputs ***
     # These should be implemented as needed with backwards compatibility for user that didn't supply the parameters
     #