Clarifying Implementation Steps of Chat 5.1

[mdueltgen]

🗣 Description

Updated 5.1 steps for editing rules for clarity.

💭 Motivation and context

Closes #448
Based on Internal Discussion about clarifying steps for rule configuration polices

🧪 Testing

N/A no code changes.

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[buidav]

Deja vu. Didn't realize we had 2 policy groups for DLP.
One for Google Chat and one for Google Drive.
Maybe DLP Rules should be moved to Common Controls since they apply across multiple apps?

Seems like DLP Rules recently expanded to Gmail as well.

[mdueltgen]

Since we have decided to move DLP to common controls I will close this PR