Provide more details about Bedrock cache metrics

[JackYPCOnline]

Description

#118
we already add metrics strands-agents/sdk-python#825, so just add print method and provide alternatives we have now.

Type of Change

• New content addition
• Content update/revision
• Structure/organization improvement
• Typo/formatting fix
• Bug fix
• Other (please describe):

Motivation and Context

Areas Affected

Screenshots

Checklist

• [x ] I have read the CONTRIBUTING document
• [x ] My changes follow the project's documentation style
• [x ] I have tested the documentation locally using mkdocs serve
• [x ] Links in the documentation are valid and working
• [x ] Images/diagrams are properly sized and formatted
• [x ] All new and existing tests pass

Additional Notes

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Changes addressed.