[CQ] remove (dead) empty methods (#8106)

More opportunistic tidying.

🧹 Remove unused empty method bodies. (Also a rogue `;`.) 
🧹 Simplify a boolean expression.

---

- [x] I’ve reviewed the contributor guide and applied the relevant
portions to this PR.

<details>
  <summary>Contribution guidelines:</summary><br>

- See our [contributor
guide]([https://github.com/dart-lang/sdk/blob/main/CONTRIBUTING.md](https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview)
for general expectations for PRs.
- Larger or significant changes should be discussed in an issue before
creating a PR.
- Dart contributions to our repos should follow the [Dart style
guide](https://dart.dev/guides/language/effective-dart) and use `dart
format`.
- Java and Kotlin contributions should strive to follow Java and Kotlin
best practices
([discussion](#8098)).
</details>

Author: pq

flutter-idea/src/io/flutter/editor/OutlineLocation.java

@@ -139,9 +139,6 @@ public OutlineLocation(
     this.indent = indent;
   }
 
-  public void dispose() {
-  }
-
   /**
    * This method must be called if the location is set to update to reflect
    * edits to the document.

flutter-idea/src/io/flutter/sdk/FlutterCreateAdditionalSettings.java

@@ -127,7 +127,7 @@ public List<String> getArgs() {
       args.add(org);
     }
 
-    if (kotlin == null || Boolean.FALSE.equals(kotlin)) {
+    if (kotlin == null || !kotlin) {
       args.add("--android-language");
       args.add("java");
     }

flutter-idea/src/io/flutter/sdk/FlutterPluginsLibraryManager.java

@@ -142,7 +142,7 @@ private void updateFlutterPluginsImpl() {
       }
 
       for (String packagePath : packagesMap.values()) {
-        if (packagePath == null) continue;;
+        if (packagePath == null) continue;
         final VirtualFile libFolder = LocalFileSystem.getInstance().findFileByPath(packagePath);
         if (libFolder == null) {
           continue;

flutter-studio/src/io/flutter/android/AndroidModuleLibraryManager.java

@@ -48,12 +48,13 @@
 import com.intellij.openapi.vfs.VirtualFileContentsChangedAdapter;
 import com.intellij.openapi.vfs.VirtualFileManager;
 import com.intellij.serviceContainer.ComponentManagerImpl;
- import com.intellij.util.ReflectionUtil;
+import com.intellij.util.ReflectionUtil;
 import com.intellij.util.modules.CircularModuleDependenciesDetector;
 import io.flutter.sdk.AbstractLibraryManager;
 import io.flutter.sdk.FlutterSdkUtil;
 import io.flutter.settings.FlutterSettings;
 import io.flutter.utils.FlutterModuleUtils;
+
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.nio.file.Path;
@@ -62,6 +63,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
 import java.util.stream.Collectors;
+
 import org.jetbrains.android.facet.AndroidFacet;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -91,7 +93,7 @@ public AndroidModuleLibraryManager(@NotNull Project project) {
   }
 
   public void update() {
-    doGradleSync(getProject(), this::scheduleAddAndroidLibraryDeps);
+    doGradleSync(getProject(), androidProject -> androidProject != null ? scheduleAddAndroidLibraryDeps(androidProject) : null);
   }
 
   private Void scheduleAddAndroidLibraryDeps(@NotNull Project androidProject) {
@@ -198,7 +200,7 @@ private void scheduleUpdate() {
     }
 
     final Runnable runnable = this::updateAndroidLibraries;
-    DumbService.getInstance(getProject()).smartInvokeLater(runnable, ModalityState.NON_MODAL);
+    DumbService.getInstance(getProject()).smartInvokeLater(runnable, ModalityState.nonModal());
   }
 
   private void updateAndroidLibraries() {
@@ -208,7 +210,7 @@ private void updateAndroidLibraries() {
     update();
   }
 
-  private void doGradleSync(Project flutterProject, Function<Project, Void> callback) {
+  private void doGradleSync(@NotNull Project flutterProject, @NotNull Function<Project, Void> callback) {
     // TODO(messick): Collect URLs for all Android modules, including those within plugins.
     VirtualFile dir = flutterProject.getBaseDir().findChild("android");
     if (dir == null) dir = flutterProject.getBaseDir().findChild(".android"); // For modules.
@@ -218,13 +220,6 @@ private void doGradleSync(Project flutterProject, Function<Project, Void> callba
     Disposer.register(flutterProject, androidProject);
 
     GradleSyncListener listener = new GradleSyncListener() {
-      public void syncTaskCreated(@NotNull Project project, @NotNull GradleSyncInvoker.Request request) {}
-
-      // TODO(messick) Remove when 3.6 is stable.
-      public void syncStarted(@NotNull Project project, boolean skipped, boolean sourceGenerationRequested) {}
-
-      public void setupStarted(@NotNull Project project) {}
-
       @Override
       public void syncSucceeded(@NotNull Project project) {
         if (isUpdating.get()) {
@@ -315,8 +310,8 @@ private class EmbeddedAndroidProject extends ProjectImpl {
     private Path path;
 
     protected EmbeddedAndroidProject(@NotNull Path filePath) {
-      super((ComponentManagerImpl) ApplicationManager.getApplication(), filePath, TEMPLATE_PROJECT_NAME);
-       path = filePath;
+      super((ComponentManagerImpl)ApplicationManager.getApplication(), filePath, TEMPLATE_PROJECT_NAME);
+      path = filePath;
     }
 
     static final String TEMPLATE_PROJECT_NAME = "_android";

flutter-studio/src/io/flutter/utils/AddToAppUtils.java

@@ -126,9 +126,6 @@ public void syncFailed(@NotNull Project project, @NotNull String errorMessage) {
       public void syncSkipped(@NotNull Project project) {
         GradleUtils.checkDartSupport(project);
       }
-
-      public void sourceGenerationFinished(@NotNull Project project) {
-      }
     };
   }