Merge pull request #14407 from rmuir/cleanThisOneAlways

make gradle eclipse always run cleanEclipse

GRADLE.CHEATSHEET

@@ -0,0 +1,7 @@
+As a quick helper, below are the equivalent commands from maven to gradle (TESTING.md has also been updated). You can also run "gradle tasks" to see all tasks that are available to run.
+clean -> clean
+test -> test
+verify -> check
+verify -Dskip.unit.tests -> integTest
+package -DskipTests -> assemble
+install -DskipTests -> install

build.gradle

@@ -158,6 +158,8 @@ allprojects {
       defaultOutputDir = new File(project.buildDir, 'eclipse')
     }
   }
+  // otherwise the eclipse merging is *super confusing*
+  tasks.eclipse.dependsOn(cleanEclipse)
 }
 
 idea {