[sysdig] Update default registry, correct host analyzer schedule, fix readme

[nestorsalceda]

Duplicated form #149

What this PR does / why we need it:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• Chart Version bumped
• Variables are documented in the README.md
• Title of the PR starts with chart name (e.g. [mychartname])
• PR only contains changes for one chart

[nestorsalceda]

Finally merged @nkraemer-sysdig

I don't know why the linter is trolling, but on any case, thank you for the PR!

[nkraemer-sysdig]

Regarding the linter I think this is the issue:

Since I'm running the CI on a fork the Expand templates for CI step is supplying " " as the secrets since I don't have access to secrets.KUBELAB_AGENT_KEY:

From the Action logs:

  find -iname "*.yaml.template" | xargs -L1 -- bash -c 'envsubst < $0 > ${0%.template}'
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
  env:
    pythonLocation: /opt/hostedtoolcache/Python/3.7.10/x64
    LD_LIBRARY_PATH: /opt/hostedtoolcache/Python/3.7.10/x64/lib
    CT_CONFIG_DIR: /opt/hostedtoolcache/ct/v3.3.0/x86_64/etc
    VIRTUAL_ENV: /opt/hostedtoolcache/ct/v3.3.0/x86_64/venv
    SECURE_API_TOKEN: 
    SECURE_AGENT_TOKEN: