Bugfix: reset available count when canceling Analysis Task (#643)

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## Description

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### Linked GitHub issue ID: #  

## Pull Request Checklist
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- [ ] Tests for the changes have been added (for bug fixes / features)
- [x] Code compiles correctly with all tests are passed.
- [x] I've read the [contributing
guide](https://github.com/microsoft/HydraLab/blob/main/CONTRIBUTING.md#making-changes-to-the-code)
and followed the recommended practices.
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[README](https://github.com/microsoft/HydraLab/blob/main/README.md) have
been reviewed and added / updated if needed (for bug fixes / features)

### Does this introduce a breaking change?
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describe the impact and migration path.*

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- [ ] No

## How you tested it
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do local test and share the screenshots, etc.*


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- [x] Bugfix
- [ ] Feature
- [ ] Technical design
- [ ] Build related changes
- [ ] Refactoring (no functional changes, no api changes)
- [ ] Code style update (formatting, renaming) or Documentation content
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- [ ] Other (please describe): 

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agent/src/main/java/com/microsoft/hydralab/agent/util/FileLoadUtil.java

@@ -65,13 +65,19 @@ public void loadAttachments(Task task) {
                     task.setAppFile(appFile);
                     break;
                 case StorageFileInfo.FileType.TEST_APP_FILE:
+                    if (!(task instanceof TestTask)) {
+                        return;
+                    }
                     File testAppFile = downloadFile(attachment);
-                    Assert.isTrue(testAppFile != null && testAppFile.exists() && task instanceof TestTask, "Download test app file failed!");
+                    Assert.isTrue(testAppFile != null && testAppFile.exists(), "Download test app file failed!");
                     ((TestTask) task).setTestAppFile(testAppFile);
                     break;
                 case StorageFileInfo.FileType.T2C_JSON_FILE:
+                    if (!(task instanceof TestTask)) {
+                        return;
+                    }
                     File testJsonFile = downloadFile(attachment);
-                    Assert.isTrue(testJsonFile != null && testJsonFile.exists() && task instanceof TestTask, "Download test json file failed!");
+                    Assert.isTrue(testJsonFile != null && testJsonFile.exists(), "Download test json file failed!");
                     ((TestTask) task).addTestJsonFile(testJsonFile);
                     break;
                 default:

center/src/main/java/com/microsoft/hydralab/center/service/DeviceAgentManagementService.java

@@ -346,12 +346,17 @@ public void updateAccessInfo(AccessInfo accessInfo) {
 
     public void cancelTestTaskById(String taskId, String reason) {
         Set<String> agentIds = testDataService.cancelTaskById(taskId, reason);
+        Task task = testDataService.getTaskDetail(taskId);
         JSONObject data = new JSONObject();
         Message message = new Message();
         data.put(Const.AgentConfig.TASK_ID_PARAM, taskId);
         message.setPath(Const.Path.TEST_TASK_CANCEL);
         message.setBody(data);
         for (String agentId : agentIds) {
+            if (Task.RunnerType.APK_SCANNER.name().equals(task.getRunnerType())) {
+                agentDeviceGroups.get(agentId).finishAnalysisTask(task.getRunnerType());
+            }
+
             AgentSessionInfo agentSession = getAgentSessionInfoByAgentId(agentId);
             if (agentSession == null || agentSession.session == null) {
                 continue;