mgmt, upgrade resources to 2025-03

[weidongxu-microsoft]

Description

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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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Testing Guidelines

• Pull request includes test coverage for the included changes.

[azure-sdk]

API Change Check

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

com.azure.resourcemanager:azure-resourcemanager-resources

[azure-sdk]

API change check

API changes are not detected in this pull request.

[Copilot]

Pull Request Overview

This pull request upgrades and extends the resources SDK to support the 2025-03 API version while introducing new properties and JSON serialization logic for deployment extensions and related components. Key changes include:

• Updating the API version from "2024-11-01" to "2025-03-01".
• Adding new properties (such as extension, identifiers, apiVersion, symbolicName) and their corresponding getters, setters, and JSON serialization logic across multiple models.
• Incorporating additional null checks in JSON writers to ensure only non-null fields are serialized.

Reviewed Changes

Copilot reviewed 46 out of 46 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
WhatIfPropertyChange.java	Adds null checks for serializing the before and after values.
WhatIfChange.java	Introduces null checks for identifiers, before, and after fields.
TargetResource.java	Adds new properties (extension, identifiers, apiVersion, symbolicName) with corresponding accessors and JSON output.
ResourceReference.java	Adds new fields (extension, resourceType, identifiers, apiVersion) as part of the resource reference model.
HttpMessage.java	Adds a null check for the content field before serialization.
ExtensionConfigPropertyType.java	Introduces a new enum for extension configuration property types.
DeploymentWhatIfProperties.java	Adds and serializes extensionConfigs with a corresponding null check.
DeploymentPropertiesExtended.java	Adds extensions and new JSON serialization logic for deployment extensions.
DeploymentProperties.java	Adds extensionConfigs field with serialization and validation logic.
DeploymentParameter.java	Adds a null check for the parameter value during JSON serialization.
DeploymentExtensionDefinition.java	Introduces the definition and JSON handling for deployment extension definitions.
DeploymentExtensionConfigItem.java	Introduces the definition and JSON handling for deployment extension config items.
ResourceManagementClientImpl.java	Updates the API version constant to "2025-03-01".
ResourceGroupExportResultInner.java	Adds a null check for the template field during JSON serialization.
GenericResourceExpandedInner.java	Adds a null check for the properties field during JSON serialization.
DeploymentExportResultInner.java	Adds a null check for the template during JSON serialization.
assets.json	Updates the asset tag to reflect the new version.
CHANGELOG.md	Documents the API version upgrade in the changelog.
api-specs.json	Updates the swagger generation argument with the new API version.