Update docs for v8.15.4 release (elastic#116574)

docs/reference/release-notes/8.15.4.asciidoc

@@ -10,18 +10,26 @@ Also see <<breaking-changes-8.15,Breaking changes in 8.15>>.
 Aggregations::
 * Always check the parent breaker with zero bytes in `PreallocatedCircuitBreakerService` {es-pull}115181[#115181]
 
+Data streams::
+* Resolve pipelines from template on lazy rollover write {es-pull}116031[#116031] (issue: {es-issue}112781[#112781])
+* [apm-data] Apply lazy rollover on index template creation {es-pull}116219[#116219] (issue: {es-issue}116230[#116230])
+
 ES|QL::
 * ESQL: Disable pushdown of WHERE past STATS {es-pull}115308[#115308] (issue: {es-issue}115281[#115281])
 
 Geo::
 * Try to simplify geometries that fail with `TopologyException` {es-pull}115834[#115834]
 
 Infra/Core::
+* Fix max file size check to use `getMaxFileSize` {es-pull}113723[#113723] (issue: {es-issue}113705[#113705])
 * Guard blob store local directory creation with `doPrivileged` {es-pull}115459[#115459]
 
 License::
 * Fix lingering license warning header in IP filter {es-pull}115510[#115510] (issue: {es-issue}114865[#114865])
 
+Machine Learning::
+* Prevent NPE if model assignment is removed while waiting to start {es-pull}115430[#115430]
+
 Search::
 * Do not exclude empty arrays or empty objects in source filtering {es-pull}112250[#112250] (issue: {es-issue}109668[#109668])
 * Fix synthetic source handling for `bit` type in `dense_vector` field {es-pull}114407[#114407] (issue: {es-issue}114402[#114402])
@@ -30,4 +38,11 @@ Vector Search::
 * Fix dim validation for bit `element_type` {es-pull}114533[#114533]
 * Support semantic_text in object fields {es-pull}114601[#114601] (issue: {es-issue}114401[#114401])
 
+[[enhancement-8.15.4]]
+[float]
+=== Enhancements
+
+Data streams::
+* Ignore warning on yaml test put template {es-pull}116200[#116200] (issue: {es-issue}116158[#116158])
+