feat(sdk): make metadata component spec gen flag configurable on pipeline level

[Tomcli]

Which issue is resolved by this Pull Request:
Resolves #

Description of your changes:
The flag for disabling component spec annotation metadata was only available on package level, we want to expose this flag on pipeline level as well so our users can control what pipeline is allowed to be tracked for metadata.

Environment tested:

• Python Version (use python --version):
• Tekton Version (use tkn version):
• Kubernetes Version (use kubectl version):
• OS (e.g. from /etc/os-release):

Checklist:

• The title for your pull request (PR) should follow our title convention. Learn more about the pull request title convention used in this repository.

[Tomcli]

/assign @yhwang

[Tomcli]

cc @typeness

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Tomcli, yhwang

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[yhwang]

/lgtm