accept list of pallet for benchmark action

when benchmark is being removed between different branch/tag the
benchmark may failed to run without updating the hard code list of
pallet in github action.

We now accept list of pallet to benchmark from the action input.

.github/workflows/benchmark.yml

@@ -2,12 +2,29 @@ name: Benchmark
 
 on:
   workflow_dispatch:
+    inputs:
+      pallet:
+        description: provided a list of pallet to run benchmark on
+        default: 'automation_time,vesting,valve,xcmp_handler'
+        required: true
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:
+  gen-params:
+    runs-on: ubuntu-latest
+    outputs:
+      pallet: ${{ steps.set-matrix.outputs.pallet }}
+    steps:
+      - id: set-matrix
+        run: |
+          # Matrix only take a list so we use fromJSON to convert raw json string data to list
+          # The input is from Github action input, which doesn't support list so we take raw string separate by ','
+          # Convert the string a,b,c -> a json array ["a", "b", "c"] with bracket and double quote properly
+          echo "::set-output name=pallet::$(echo -n ${{ inputs.tag }} | jq --raw-input --slurp 'split(",")' -c)"
+
   build-binary:
     runs-on: self-hosted
     steps:
@@ -28,17 +45,15 @@ jobs:
           name: oak-collator
           path: artifacts/
           retention-days: 1
+
   run-benchmarks:
     name: Run Benchmarks
     runs-on: self-hosted
-    needs: build-binary
+    needs: [gen-params, build-binary]
     strategy:
       matrix:
-        pallet:
-          - automation_time
-          - vesting
-          - valve
-          - xcmp_handler
+         pallet: ${{ fromJSON(needs.gen-params.outputs.pallet) }}
+
     steps:
       - name: Download binary
         uses: actions/download-artifact@v2