Hardcode version condition instead of calling minimumCompatibilityVer…

…sion() (elastic#100102)

This is one of the few uses of Version#minimumCompatibilityVersion that isn't covered by other planned work. Since the minimum compatibility version for 7.14.0 is always going to be 6.8.0, we can just hardcode the value.

qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/FullClusterRestartIT.java

@@ -1869,7 +1869,7 @@ public void testTransportCompressionSetting() throws IOException {
         assumeTrue("the old transport.compress setting existed before 7.14", getOldClusterVersion().before(Version.V_7_14_0));
         assumeTrue(
             "Early versions of 6.x do not have cluster.remote* prefixed settings",
-            getOldClusterVersion().onOrAfter(Version.V_7_14_0.minimumCompatibilityVersion())
+            getOldClusterVersion().onOrAfter(Version.fromString("6.8.0"))
         );
         if (isRunningAgainstOldCluster()) {
             final Request putSettingsRequest = new Request("PUT", "/_cluster/settings");