Upgrade to Gradle 6.1 (elastic#50453)

(cherry picked from commit bdd7bda)

Author: mark-vieira

.ci/java-versions.properties

@@ -8,6 +8,3 @@ ES_BUILD_JAVA=openjdk13
 ES_RUNTIME_JAVA=java8
 GRADLE_TASK=build
 GRADLE_EXTRA_ARGS=
-
-# Workaround for https://github.com/gradle/gradle/issues/11426
-OPENSHIFT_IP=0.0.0.0

buildSrc/src/main/resources/minimumGradleVersion

@@ -1 +1 @@
-6.0.1
+6.1

distribution/bwc/build.gradle

@@ -162,12 +162,6 @@ bwcVersions.forPreviousUnreleased { BwcVersions.UnreleasedVersionInfo unreleased
         spoolOutput = true
         workingDir = checkoutDir
         doFirst {
-          // TODO: Remove this once we've updated to Gradle 6.1
-          // Workaround for https://github.com/gradle/gradle/issues/11426
-          if (GradleVersion.version(file("${ checkoutDir}/buildSrc/src/main/resources/minimumGradleVersion").text.trim()) != GradleVersion.current()) {
-            environment = environment.findAll { key, val -> key != 'OPENSHIFT_IP' }
-          }
-
           // Execution time so that the checkouts are available
           List<String> lines = file("${checkoutDir}/.ci/java-versions.properties").readLines()
           environment(

gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionSha256Sum=6f6cfdbb12a577c3845522a1c7fbfe1295ea05d87edabedd4e23fd2bf02b88b1
+distributionSha256Sum=634f972af958e3c753aeb42d7a688fab6820b527a0aef9eed03d7f3f6f9c7c06