Elasticsearch: Remove support for EOL 6.x versions

Remove support for Elasticsearch versions 6.[2-4], as they became EOL
recently [1]. Versions 6.{0,1} were never added in for Gerrit support.

[1] https://www.elastic.co/support/eol

Feature: Issue 12527
Change-Id: Ib0971eb98df4586920d364170d17591dd19aeed3
diff --git a/java/com/google/gerrit/elasticsearch/ElasticVersion.java b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
index 2d023cf..82816fb 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticVersion.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
@@ -18,9 +18,6 @@
 import java.util.regex.Pattern;
 
 public enum ElasticVersion {
-  V6_2("6.2.*"),
-  V6_3("6.3.*"),
-  V6_4("6.4.*"),
   V6_5("6.5.*"),
   V6_6("6.6.*"),
   V6_7("6.7.*"),
diff --git a/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java b/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
index 879c7c5..e4b45ed 100644
--- a/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
+++ b/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
@@ -38,12 +38,6 @@
 
   private static String getImageName(ElasticVersion version) {
     switch (version) {
-      case V6_2:
-        return "blacktop/elasticsearch:6.2.4";
-      case V6_3:
-        return "blacktop/elasticsearch:6.3.2";
-      case V6_4:
-        return "blacktop/elasticsearch:6.4.3";
       case V6_5:
         return "blacktop/elasticsearch:6.5.4";
       case V6_6:
diff --git a/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java b/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
index a338371..5a3d6da 100644
--- a/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
+++ b/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
@@ -25,15 +25,6 @@
 
   @Test
   public void supportedVersion() throws Exception {
-    assertThat(ElasticVersion.forVersion("6.2.0")).isEqualTo(ElasticVersion.V6_2);
-    assertThat(ElasticVersion.forVersion("6.2.4")).isEqualTo(ElasticVersion.V6_2);
-
-    assertThat(ElasticVersion.forVersion("6.3.0")).isEqualTo(ElasticVersion.V6_3);
-    assertThat(ElasticVersion.forVersion("6.3.2")).isEqualTo(ElasticVersion.V6_3);
-
-    assertThat(ElasticVersion.forVersion("6.4.0")).isEqualTo(ElasticVersion.V6_4);
-    assertThat(ElasticVersion.forVersion("6.4.1")).isEqualTo(ElasticVersion.V6_4);
-
     assertThat(ElasticVersion.forVersion("6.5.0")).isEqualTo(ElasticVersion.V6_5);
     assertThat(ElasticVersion.forVersion("6.5.1")).isEqualTo(ElasticVersion.V6_5);
 
@@ -78,9 +69,6 @@
 
   @Test
   public void atLeastMinorVersion() throws Exception {
-    assertThat(ElasticVersion.V6_2.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
-    assertThat(ElasticVersion.V6_3.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
-    assertThat(ElasticVersion.V6_4.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
     assertThat(ElasticVersion.V6_5.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
     assertThat(ElasticVersion.V6_6.isAtLeastMinorVersion(ElasticVersion.V6_7)).isFalse();
     assertThat(ElasticVersion.V6_7.isAtLeastMinorVersion(ElasticVersion.V6_7)).isTrue();
@@ -96,9 +84,6 @@
 
   @Test
   public void version6OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_2.isV6OrLater()).isTrue();
-    assertThat(ElasticVersion.V6_3.isV6OrLater()).isTrue();
-    assertThat(ElasticVersion.V6_4.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_5.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_6.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_7.isV6OrLater()).isTrue();
@@ -114,9 +99,6 @@
 
   @Test
   public void version7OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_2.isV7OrLater()).isFalse();
-    assertThat(ElasticVersion.V6_3.isV7OrLater()).isFalse();
-    assertThat(ElasticVersion.V6_4.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_5.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_6.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_7.isV7OrLater()).isFalse();