Bump jetty.version in /examples (#2067)

Bumps `jetty.version` from 9.4.17.v20190418 to 9.4.35.v20201120.

Updates `jetty-client` from 9.4.17.v20190418 to 9.4.35.v20201120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.17.v20190418...jetty-9.4.35.v20201120)

Updates `jetty-server` from 9.4.17.v20190418 to 9.4.35.v20201120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.17.v20190418...jetty-9.4.35.v20201120)

Updates `jetty-servlet` from 9.4.17.v20190418 to 9.4.35.v20201120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.17.v20190418...jetty-9.4.35.v20201120)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

examples/pom.xml

@@ -11,7 +11,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <!-- change to the version you want to use. -->
-    <jetty.version>9.4.17.v20190418</jetty.version>
+    <jetty.version>9.4.35.v20201120</jetty.version>
     <opencensus.version>0.28.1</opencensus.version> <!-- LATEST_OPENCENSUS_RELEASE_VERSION -->
     <grpc.version>1.32.2</grpc.version> <!-- CURRENT_GRPC_VERSION -->
   </properties>