Update pr-checks.yml

Author: Vacxe

.github/workflows/pr-checks.yml

@@ -67,7 +67,7 @@ jobs:
       - name: Run tests on Firebase Test Lab for API ${{ matrix.api }}
         uses: vacxe/[email protected]
         with:
-          service-account: ${{ secrets.FIREBASE_TESTLAB_JSON }}
+          service-account: "Fake token"
           app: apk/sample-debug.apk
           test: apk/sample-debug-androidTest.apk
           device-id: MediumPhone.arm