IDEA-210281 Cleanup Gradle settings: UseQualifiedModuleNames hidden + CreateEmptyContentRootDirectories dropped

* UseQualifiedModuleNames restored backward and forward compatibility.

GitOrigin-RevId: 25c423fcb2f41b8c696d214b7e8ead113a77b7cc

platform/external-system-api/src/com/intellij/openapi/externalSystem/settings/ExternalProjectSettings.java

@@ -1,6 +1,7 @@
 // Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.externalSystem.settings;
 
+import com.intellij.openapi.externalSystem.util.ExternalSystemApiUtil;
 import com.intellij.openapi.util.Comparing;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -29,11 +30,16 @@ public abstract class ExternalProjectSettings implements Comparable<ExternalProj
   }
 
   private boolean myUseAutoImport;
-  private boolean myUseQualifiedModuleNames = true;
+  private boolean myUseQualifiedModuleNames = !ExternalSystemApiUtil.isJavaCompatibleIde(); // backward-compatible defaults
 
   @SuppressWarnings("DeprecatedIsStillUsed") @Deprecated // left for settings backward-compatibility
   private boolean myCreateEmptyContentRootDirectories;
 
+  // Used to gradually migrate new project to the new defaults.
+  public void setupNewProjectDefault() {
+    myUseQualifiedModuleNames = true;
+  }
+
   public String getExternalProjectPath() {
     return myExternalProjectPath;
   }

platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/project/wizard/AbstractExternalModuleBuilder.java

@@ -25,6 +25,7 @@ public abstract class AbstractExternalModuleBuilder<S extends ExternalProjectSet
                                           @NotNull final S externalProjectSettings) {
     myExternalSystemId = externalSystemId;
     myExternalProjectSettings = externalProjectSettings;
+    externalProjectSettings.setupNewProjectDefault();
     Icon icon = ExternalSystemUiUtil.getUiAware(externalSystemId).getProjectIcon();
     myIcon = icon == null ? super.getNodeIcon() : icon;
   }

platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/settings/AbstractImportFromExternalSystemControl.java

@@ -81,6 +81,8 @@ public abstract class AbstractImportFromExternalSystemControl<
     myExternalSystemId = externalSystemId;
     mySystemSettings = systemSettings;
     myProjectSettings = projectSettings;
+    myProjectSettings.setupNewProjectDefault();
+
     myProjectSettingsControl = createProjectSettingsControl(projectSettings);
     mySystemSettingsControl = createSystemSettingsControl(systemSettings);
     myShowProjectFormatPanel = showProjectFormatPanel;