Refactor Github Action per b/485167538

Author: benknutson-google

.github/workflows/build-sample.yml

@@ -51,7 +51,9 @@ jobs:
           distribution: 'zulu'
 
       - name: Generate cache key
-        run: ./scripts/checksum.sh ${{ inputs.path }} checksum.txt
+        run: ./scripts/checksum.sh ${INPUTS_PATH} checksum.txt
+        env:
+          INPUTS_PATH: ${{ inputs.path }}
 
       - uses: actions/cache@v5
         with: