Remove duplicate Indices on PrimaryKeys.

[Sagar0-0]

🎯 Goal

Remove unnecessary @ColumnInfo(index = true) from a @PrimaryKey column, as Room and SQLite automatically index primary keys.

🛠 Implementation details

Removed @ColumnInfo(index = true) annotation from the primary key column in these two entity..
This cleanup helps avoid redundant annotations and keeps the entity definition minimal and accurate.

🧪 Testing

No runtime or behavioral impact expected, as primary keys are indexed by default.
Verified that Room compiles the schema correctly and no migrations are required for this change.

☑️Contributor Checklist

General

• I have signed the Stream CLA (required)
• Assigned a person / code owner group (required)
• Thread with the PR link started in a respective Slack channel (#android-chat-core or #android-chat-ui) (required)
• PR is linked to the GitHub issue it resolves

Code & documentation

• Changelog is updated with client-facing changes
• New code is covered by unit tests
• Comparison screenshots added for visual changes
• Affected documentation updated (KDocs, docusaurus, tutorial)

☑️Reviewer Checklist

• UI Components sample runs & works
• Compose sample runs & works
• UI Changes correct (before & after images)
• Bugs validated (bugfixes)
• New feature tested and works
• Release notes and docs clearly describe changes
• All code we touched has new or updated KDocs

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