Handle RPCError when VM service disappears while invoking `VmService.getIsolate` (#74528)

* Handle RPCError when VM service disappears while invoking `VmService.getIsolate`

* Add test

packages/flutter_tools/lib/src/vmservice.dart

@@ -791,7 +791,10 @@ extension FlutterVmService on vm_service.VmService {
     return getIsolate(isolateId)
       .catchError((dynamic error, StackTrace stackTrace) {
         return null;
-      }, test: (dynamic error) => error is vm_service.SentinelException);
+      }, test: (dynamic error) {
+        return (error is vm_service.SentinelException) ||
+          (error is vm_service.RPCError && error.code == RPCErrorCodes.kServiceDisappeared);
+      });
   }
 
   /// Create a new development file system on the device.

packages/flutter_tools/test/general.shard/vmservice_test.dart

@@ -333,6 +333,23 @@ void main() {
     expect(fakeVmServiceHost.hasRemainingExpectations, false);
   });
 
+  testWithoutContext('getIsolateOrNull returns null if service disappears ', () async {
+    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
+      requests: <VmServiceExpectation>[
+        const FakeVmServiceRequest(method: 'getIsolate', args: <String, Object>{
+          'isolateId': 'isolate/123',
+        }, errorCode: RPCErrorCodes.kServiceDisappeared),
+      ]
+    );
+
+    final vm_service.Isolate isolate = await fakeVmServiceHost.vmService.getIsolateOrNull(
+      'isolate/123',
+    );
+    expect(isolate, null);
+
+    expect(fakeVmServiceHost.hasRemainingExpectations, false);
+  });
+
   testWithoutContext('getFlutterViews polls until a view is returned', () async {
     final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
       requests: <VmServiceExpectation>[