[CQ] remove unused imports (flutter#8538)

Clean up a handful of unused imports.

---

- [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](flutter#8098)).
</details>

Author: pq

src/io/flutter/android/AndroidSdk.java

@@ -17,7 +17,6 @@
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.vfs.LocalFileSystem;
 import com.intellij.openapi.vfs.VirtualFile;
-import io.flutter.FlutterUtils;
 import io.flutter.logging.PluginLogger;
 import io.flutter.settings.FlutterSettings;
 import org.jetbrains.annotations.NotNull;
@@ -132,7 +131,8 @@ public void onTextAvailable(@NotNull ProcessEvent event, @NotNull Key outputType
     catch (ExecutionException | RuntimeException e) {
       if (FlutterSettings.getInstance().isFilePathLoggingEnabled()) {
         LOG.warn("Error listing android emulators", e);
-      } else {
+      }
+      else {
         LOG.warn("Error listing android emulators");
       }
       return Collections.emptyList();

src/io/flutter/run/FlutterPositionMapper.java

@@ -20,7 +20,6 @@
 import com.jetbrains.lang.dart.analyzer.DartAnalysisServerService;
 import com.jetbrains.lang.dart.util.DartResolveUtil;
 import com.jetbrains.lang.dart.util.DartUrlResolver;
-import io.flutter.FlutterUtils;
 import io.flutter.dart.DartPlugin;
 import io.flutter.logging.PluginLogger;
 import io.flutter.utils.OpenApiUtils;
@@ -32,7 +31,12 @@
 import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
-import java.util.*;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 
 /**
@@ -278,7 +282,7 @@ private XSourcePosition getSourcePosition(@NotNull final String isolateId, @NotN
   String getRemoteSourceRoot() {
     return remoteSourceRoot;
   }
-  
+
   @Nullable
   protected VirtualFile findLocalFile(@NotNull String uri) {
     return findLocalFile(uri, null);

src/io/flutter/run/OpenDevToolsAction.java

@@ -22,7 +22,6 @@
 import io.flutter.run.daemon.DevToolsService;
 import io.flutter.run.daemon.FlutterApp;
 import io.flutter.sdk.FlutterSdk;
-import io.flutter.settings.FlutterSettings;
 import io.flutter.utils.AsyncUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

src/io/flutter/run/daemon/DaemonApi.java

@@ -6,14 +6,18 @@
 package io.flutter.run.daemon;
 
 import com.google.common.base.Charsets;
-import com.google.gson.*;
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.JsonSyntaxException;
 import com.intellij.execution.process.ProcessAdapter;
 import com.intellij.execution.process.ProcessEvent;
 import com.intellij.execution.process.ProcessHandler;
 import com.intellij.execution.process.ProcessOutputTypes;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.Key;
-import io.flutter.FlutterUtils;
 import io.flutter.logging.PluginLogger;
 import io.flutter.settings.FlutterSettings;
 import io.flutter.utils.JsonUtils;
@@ -25,7 +29,13 @@
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
-import java.util.*;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Deque;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;

src/io/flutter/run/daemon/DevToolsService.java

@@ -5,14 +5,9 @@
  */
 package io.flutter.run.daemon;
 
-import com.intellij.execution.process.ProcessOutput;
-import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.progress.impl.BackgroundableProcessIndicator;
 import com.intellij.openapi.project.Project;
-import io.flutter.console.FlutterConsoles;
-import io.flutter.sdk.FlutterCommand;
-import io.flutter.sdk.FlutterSdk;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 

src/io/flutter/sdk/AndroidEmulatorManager.java

@@ -13,7 +13,6 @@
 import io.flutter.android.AndroidEmulator;
 import io.flutter.android.AndroidSdk;
 import io.flutter.logging.PluginLogger;
-import io.flutter.settings.FlutterSettings;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;