feat: add eslintignore for sameple generated code (#1302) (#905)

Source-Link: googleapis/synthtool@b801276
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-nodejs:latest@sha256:ba3f2990fefe465f89834e4c46f847ddb141afa54daa6a1d462928fa679ed143

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

packages/google-cloud-dialogflow/.eslintignore

@@ -4,3 +4,4 @@ test/fixtures
 build/
 docs/
 protos/
+samples/generated/