[CQ] Java 16: migrate to Records (#8240)

JLS 16 brings
[records](https://docs.oracle.com/javase/specs/jls/se21/html/jls-8.html#jls-8.10)
to Java which (like Dart) gives us a more terse way to describe simple
value aggregating classes.

This PR migrates 4 simple classes to Records. 

(I brought attention to a few things in PR comments to amplify some Dart
comparisons.)

---

- [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/FlutterIconLineMarkerProvider.java

@@ -382,18 +382,7 @@ public double findPattern(@NotNull String t, @NotNull String p) {
     return jw.similarity(t, p);
   }
 
-  static class IconInfo {
-    final @NotNull String iconName;
-    final @NotNull String className;
-    final @Nullable String familyName;
-    final @NotNull String codepoint;
-
-    IconInfo(@NotNull String className, @NotNull String iconName, @Nullable String familyName, @NotNull String codepoint) {
-      this.className = className;
-      this.iconName = iconName;
-      this.familyName = familyName;
-      this.codepoint = codepoint;
-    }
+  record IconInfo(@NotNull String className, @NotNull String iconName, @Nullable String familyName, @NotNull String codepoint) {
   }
 
   static class IconInfoVisitor extends DartRecursiveVisitor {

flutter-idea/src/io/flutter/run/ObservatoryFile.java

@@ -175,13 +175,10 @@ ObservatoryFile downloadOrGet(@NotNull String scriptId, boolean wantSnapshot) {
     }
   }
 
-  private static class Position {
-    final int line; // zero-based
-    final int column; // zero-based
-
-    Position(int line, int column) {
-      this.line = line;
-      this.column = column;
-    }
+  /**
+   * @param line   zero-based
+   * @param column zero-based
+   */
+  private record Position(int line, int column) {
   }
 }

flutter-idea/src/io/flutter/run/common/CommonTestConfigUtils.java

@@ -242,18 +242,8 @@ private void populateTestTypeMap(@NotNull FlutterOutline outline, @NotNull PsiFi
    * <p>
    * Used to ensure that we don't get stuck with out-of-date line markers.
    */
-  private static class LineMarkerUpdatingListener implements ActiveEditorsOutlineService.Listener {
-    @NotNull final CommonTestConfigUtils commonTestConfigUtils;
-    @NotNull final Project project;
-    @NotNull final ActiveEditorsOutlineService service;
-
-    private LineMarkerUpdatingListener(@NotNull CommonTestConfigUtils commonTestConfigUtils,
-                                       @NotNull Project project,
-                                       @NotNull ActiveEditorsOutlineService service) {
-      this.commonTestConfigUtils = commonTestConfigUtils;
-      this.project = project;
-      this.service = service;
-    }
+  private record LineMarkerUpdatingListener(@NotNull CommonTestConfigUtils commonTestConfigUtils, @NotNull Project project,
+                                            @NotNull ActiveEditorsOutlineService service) implements ActiveEditorsOutlineService.Listener {
 
     @Override
     public void onOutlineChanged(@NotNull String filePath, @Nullable FlutterOutline outline) {

flutter-idea/src/io/flutter/vmService/ServiceExtensionState.java

@@ -7,21 +7,5 @@
 
 import org.jetbrains.annotations.Nullable;
 
-public final class ServiceExtensionState {
-  private final boolean enabled;
-  @Nullable private final Object value;
-
-  public ServiceExtensionState(boolean enabled, @Nullable Object value) {
-    this.enabled = enabled;
-    this.value = value;
-  }
-
-  public boolean isEnabled() {
-    return enabled;
-  }
-
-  @Nullable
-  public Object getValue() {
-    return value;
-  }
+public record ServiceExtensionState(boolean enabled, @Nullable Object value) {
 }

flutter-idea/src/io/flutter/vmService/VMServiceManager.java

@@ -294,7 +294,7 @@ else if (!stream.getValue()) {
       restoreExtensionFromDevice(name);
 
       // Restore any previously true states by calling their service extensions.
-      if (getServiceExtensionState(name).getValue().isEnabled()) {
+      if (getServiceExtensionState(name).getValue().enabled()) {
         restoreServiceExtensionState(name);
       }
     }
@@ -347,7 +347,7 @@ private void restoreServiceExtensionState(String name) {
         return;
       }
 
-      @Nullable final Object value = getServiceExtensionState(name).getValue().getValue();
+      @Nullable final Object value = getServiceExtensionState(name).getValue().value();
 
       if (value instanceof Boolean) {
         app.callBooleanExtension(name, (Boolean)value);