[ML] Adjust BWC version following backport (#47996)

The BWC version for auto-stopping datafeeds
should be 7.5.0 now #47922 is backported.

Author: droberts195

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/datafeed/DatafeedConfig.java

@@ -223,8 +223,7 @@ public DatafeedConfig(StreamInput in) throws IOException {
         this.chunkingConfig = in.readOptionalWriteable(ChunkingConfig::new);
         this.headers = Collections.unmodifiableMap(in.readMap(StreamInput::readString, StreamInput::readString));
         delayedDataCheckConfig = in.readOptionalWriteable(DelayedDataCheckConfig::new);
-        // TODO: change version in backport
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_7_5_0)) {
             maxEmptySearches = in.readOptionalVInt();
         } else {
             maxEmptySearches = null;
@@ -429,8 +428,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalWriteable(chunkingConfig);
         out.writeMap(headers, StreamOutput::writeString, StreamOutput::writeString);
         out.writeOptionalWriteable(delayedDataCheckConfig);
-        // TODO: change version in backport
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_7_5_0)) {
             out.writeOptionalVInt(maxEmptySearches);
         }
     }

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/datafeed/DatafeedUpdate.java

@@ -144,8 +144,7 @@ public DatafeedUpdate(StreamInput in) throws IOException {
         this.scrollSize = in.readOptionalVInt();
         this.chunkingConfig = in.readOptionalWriteable(ChunkingConfig::new);
         delayedDataCheckConfig = in.readOptionalWriteable(DelayedDataCheckConfig::new);
-        // TODO: change version in backport
-        if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_7_5_0)) {
             maxEmptySearches = in.readOptionalInt();
         } else {
             maxEmptySearches = null;
@@ -193,8 +192,7 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalVInt(scrollSize);
         out.writeOptionalWriteable(chunkingConfig);
         out.writeOptionalWriteable(delayedDataCheckConfig);
-        // TODO: change version in backport
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_7_5_0)) {
             out.writeOptionalInt(maxEmptySearches);
         }
     }