Bump kuberentes_metadata_filter plugin version

[DevAndrewGeorge]

For those of us using the Docker image provided in this repo in AWS EKS, we've received a notice:

We have identified applications running in one or more of your Amazon EKS clusters that are not refreshing service account tokens. Applications making requests to Kubernetes API server with expired tokens will fail. You can resolve the issue by updating your application and its dependencies to use newer versions of Kubernetes client SDK that automatically refreshes the tokens.

The library/plugin causing triggering this notification has since been patched.

This PR bumps the version of affected plugin to resolve the issue in the relevant image.

(It also seems that Gemfile.lock hasn't been updated in a while.)

[vmwclabot]

@DevAndrewGeorge, you must sign every commit in this pull request acknowledging our Developer Certificate of Origin before your changes are merged. This can be done by adding Signed-off-by: John Doe <john.doe@email.org> to the last line of each Git commit message. The e-mail address used to sign must match the e-mail address of the Git author. Click here to view the Developer Certificate of Origin agreement.

• Commit 7eecfcb must be signed by ageorge@gumgum.com

[vmwclabot]

@DevAndrewGeorge, you must sign every commit in this pull request acknowledging our Developer Certificate of Origin before your changes are merged. This can be done by adding Signed-off-by: John Doe <john.doe@email.org> to the last line of each Git commit message. The e-mail address used to sign must match the e-mail address of the Git author. Click here to view the Developer Certificate of Origin agreement.

• Commit 7eecfcb must be signed by ageorge@gumgum.com
• Commit acb2133 must be signed by ageorge@gumgum.com