Fix release pipeline yaml (#733)

There were two issues:

* The indentation for the PowerShell script task was off,
  causing a parsing error
* The flighting task needed to be named so that the Aero
  task would be able to reference its output variable.

build/pipelines/templates/prepare-release-internalonly.yaml

@@ -139,6 +139,7 @@ jobs:
 
   - task: MS-RDX-MRO.windows-store-publish-dev.flight-task.store-flight@2
     displayName: 'Flight StoreBroker Payload to team ring'
+    name: StoreBrokerFlight
     inputs:
       serviceEndpoint: StoreBrokerProxy
       appId: '$(AppId)'
@@ -158,7 +159,7 @@ jobs:
     inputs:
       ProductId: '$(ProductId)'
       FlightId: '$(FlightId)'
-      SubmissionId: '$(null.WS_SubmissionId)'
+      SubmissionId: '$(StoreBrokerFlight.WS_SubmissionId)'
       SubmissionDataPath: '$(SBPackagePath)\SBCalculator.json'
       PackagePath: '$(SBPackagePath)\SBCalculator.zip'
       AeroEnvironment: Production