docs(java): Add docs for propagateTraceparent option (#14859)

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Add docs for getsentry/sentry-java#4671

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Author: markushi

docs/platforms/android/configuration/options.mdx

@@ -327,6 +327,12 @@ If <PlatformIdentifier name="trace-propagation-targets" /> is not provided, trac
 
 </ConfigKey>
 
+<ConfigKey name="propagate-traceparent">
+
+Controls whether the SDK should propagate the W3C `traceparent` HTTP header alongside the `sentry-trace` and `baggage` headers for distributed tracing. This option defaults to `false` and is available starting from SDK version 8.22.0.
+
+</ConfigKey>
+
 <ConfigKey name="trace-options-requests">
 
 Set this boolean to `false` to disable tracing for `OPTIONS` requests. This options default value will likely be changed in the next major version, meaning you will have to set it to `true` if you want to keep tracing `OPTIONS` requests.

docs/platforms/android/tracing/trace-propagation/index.mdx

@@ -63,3 +63,9 @@ SentryAndroid.init(context, { options ->
     ))
 })
 ```
+
+## W3C Traceparent Header Support
+
+Starting from version 8.22.0, the Java SDK also supports the W3C `traceparent` HTTP header for outgoing requests. This header follows the [W3C Trace Context specification](https://develop.sentry.dev/sdk/telemetry/traces/distributed-tracing/#w3c-trace-context-header) and provides interoperability with other tracing systems that support this standard.
+
+To enable W3C `traceparent` header propagation, set the [`propagateTraceparent`](/platforms/android/configuration/options/#propagate-traceparent) option to `true`. When enabled, the `traceparent` header will be propagated alongside the `sentry-trace` and `baggage` headers to outgoing HTTP requests. Like the other headers, it's attached to all requests by default, or only to requests matching your `tracePropagationTargets` configuration if you've specified one.

docs/platforms/java/common/configuration/options.mdx

@@ -277,6 +277,12 @@ If <PlatformIdentifier name="trace-propagation-targets" /> is not provided, trac
 
 </ConfigKey>
 
+<ConfigKey name="propagate-traceparent">
+
+Controls whether the SDK should propagate the W3C `traceparent` HTTP header alongside the `sentry-trace` and `baggage` headers for distributed tracing. This option defaults to `false` and is available starting from SDK version 8.22.0.
+
+</ConfigKey>
+
 <ConfigKey name="trace-options-requests">
 
 Set this boolean to `false` to disable tracing for `OPTIONS` requests. This options default value will likely be changed in the next major version, meaning you will have to set it to `true` if you want to keep tracing `OPTIONS` requests.

docs/platforms/java/common/tracing/trace-propagation/index.mdx

@@ -62,4 +62,10 @@ Sentry.init(context, { options ->
         "https://api.myproject.org/"
     ))
 })
-```
+```
+
+## W3C Traceparent Header Support
+
+Starting from version 8.22.0, the Java SDK also supports the W3C `traceparent` HTTP header for outgoing requests. This header follows the [W3C Trace Context specification](https://develop.sentry.dev/sdk/telemetry/traces/distributed-tracing/#w3c-trace-context-header) and provides interoperability with other tracing systems that support this standard.
+
+To enable W3C `traceparent` header propagation, set the [`propagateTraceparent`](/platforms/java/configuration/options/#propagate-traceparent) option to `true`. When enabled, the `traceparent` header will be propagated alongside the `sentry-trace` and `baggage` headers to outgoing HTTP requests. Like the other headers, it's attached to all requests by default, or only to requests matching your `tracePropagationTargets` configuration if you've specified one.