Adapt version after backport of elastic#61779 (elastic#62029)

This commit adapts the bwc version checks added in elastic#61779 and disable
bwc tests until the backport elastic#62028 is merged.

build.gradle

@@ -174,8 +174,8 @@ tasks.register("verifyVersions") {
  * after the backport of the backcompat code is complete.
  */
 
-boolean bwc_tests_enabled = true
-final String bwc_tests_disabled_issue = "" /* place a PR link here when committing bwc changes */
+boolean bwc_tests_enabled = false
+final String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/62028" /* place a PR link here when committing bwc changes */
 if (bwc_tests_enabled == false) {
   if (bwc_tests_disabled_issue.isEmpty()) {
     throw new GradleException("bwc_tests_disabled_issue must be set when bwc_tests_enabled == false")

server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalTerms.java

@@ -192,7 +192,7 @@ protected InternalTerms(String name,
     protected InternalTerms(StreamInput in) throws IOException {
        super(in);
        reduceOrder = InternalOrder.Streams.readOrder(in);
-       if (in.getVersion().onOrAfter(Version.V_8_0_0)) {
+       if (in.getVersion().onOrAfter(Version.V_7_10_0)) {
            order = InternalOrder.Streams.readOrder(in);
        } else {
            order = reduceOrder;
@@ -203,7 +203,7 @@ protected InternalTerms(StreamInput in) throws IOException {
 
     @Override
     protected final void doWriteTo(StreamOutput out) throws IOException {
-        if (out.getVersion().onOrAfter(Version.V_8_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_7_10_0)) {
             reduceOrder.writeTo(out);
         }
         order.writeTo(out);