EQL: Refine bwc version checks on EqlSearchRequest (#91510)

Author: luigidellaquila

docs/changelog/91510.yaml

@@ -0,0 +1,5 @@
+pr: 91510
+summary: Refine bwc version checks on `EqlSearchRequest`
+area: EQL
+type: bug
+issues: []

x-pack/plugin/eql/src/main/java/org/elasticsearch/xpack/eql/action/EqlSearchRequest.java

@@ -118,7 +118,7 @@ public EqlSearchRequest(StreamInput in) throws IOException {
         this.waitForCompletionTimeout = in.readOptionalTimeValue();
         this.keepAlive = in.readOptionalTimeValue();
         this.keepOnCompletion = in.readBoolean();
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_7_17_8)) {
             resultPosition = in.readString();
         }
         if (in.getVersion().onOrAfter(Version.V_7_13_0)) {
@@ -436,7 +436,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalTimeValue(waitForCompletionTimeout);
         out.writeOptionalTimeValue(keepAlive);
         out.writeBoolean(keepOnCompletion);
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_7_17_8)) {
             out.writeString(resultPosition);
         }
         if (out.getVersion().onOrAfter(Version.V_7_13_0)) {

x-pack/plugin/eql/src/test/java/org/elasticsearch/xpack/eql/action/EqlSearchRequestTests.java

@@ -132,7 +132,7 @@ protected EqlSearchRequest mutateInstanceForVersion(EqlSearchRequest instance, V
         mutatedInstance.keepOnCompletion(instance.keepOnCompletion());
         mutatedInstance.fetchFields(version.onOrAfter(Version.V_7_13_0) ? instance.fetchFields() : null);
         mutatedInstance.runtimeMappings(version.onOrAfter(Version.V_7_13_0) ? instance.runtimeMappings() : emptyMap());
-        mutatedInstance.resultPosition(version.onOrAfter(Version.V_8_0_0) ? instance.resultPosition() : "tail");
+        mutatedInstance.resultPosition(version.onOrAfter(Version.V_7_17_8) ? instance.resultPosition() : "tail");
 
         return mutatedInstance;
     }