Fix workflow file syntax

Author: gsingh04

.github/workflows/run-unit-test.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   unittest:
     name: Unit Test Check
-    if: {{ (github.repository_owner != 'aws-solutions' && github.event_name == 'push') || (github.repository_owner == 'aws-solutions' && github.event_name == 'pull_request')}}
+    if: ${{ (github.repository_owner != 'aws-solutions' && github.event_name == 'push') || (github.repository_owner == 'aws-solutions' && github.event_name == 'pull_request') }}
     runs-on: ubuntu-latest
     strategy:
       matrix: