Allow proxy for client telemetry

[xinlian12]

Description

Fix issue: #29023. Customer would like to ONLY enable proxy for their clientTelemetry requests. But currently, clientTelemetryRequests and gatewayRequests are sharing the same HttpClient which makes it impossible. So in this PR, internally we separate the httpclients and allow customer to config the proxy through System property.

Example code:

 System.setProperty(
                        "COSMOS.CLIENT_TELEMETRY_PROXY_OPTIONS_CONFIG",
                       "{\"type\":\"HTTP\", \"host\": \"localhost\", \"port\": 8080}");

If an SDK is being regenerated based on a new swagger spec, a link to the pull request containing these swagger spec changes has been included above.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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• Title of the pull request is clear and informative.
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Testing Guidelines

• Pull request includes test coverage for the included changes.

[azure-sdk]

API change check

APIView has identified API level changes in this PR and created following API reviews.

azure-cosmos

[kushagraThapar]

Overall looks good to me, with a new implementation config that will be used just for ClientTelemetry.
However, one thing to think about our Metric Registry exposure for certain customers, where do you think that information can go?
Basically these 2 issues: #29025
#29026

[xinlian12]

Overall looks good to me, with a new implementation config that will be used just for ClientTelemetry.
However, one thing to think about our Metric Registry exposure for certain customers, where do you think that information can go?
Basically these 2 issues: #29025
#29026

Good point, The name should definitely change then. ClientTelemetryConnectionConfig -> ClientTelemetryConfig

[xinlian12]

/azp run java - cosmos

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[FabianMeiswinkel]

LGTM - except for the test comment (please revert all the places where you use withClientTelemetryEnabled(false) - this is the default - those changes shouldn't be necessary.

[xinlian12]

/azp run java - cosmos

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[xinlian12]

/azp run java - cosmos

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).