在循环运行 UiAutomation 测试用例时，我遇到了 UiAutomation Not Connected 的问题。
AndroidRuntime：致命异常：Timer-0 AndroidRuntime：进程：com.android.imstressautomation，PID：13697 AndroidRuntime：java.lang.IllegalStateException：UiAutomation 未连接！AndroidRuntime: android.app.UiAutomation.throwIfNotConnectedLocked(UiAutomation.java:971) AndroidRuntime: android.app.UiAutomation.waitForIdle(UiAutomation.java:577) AndroidRuntime:android.support.test.uiautomator.UiAutomatorBridge.waitForIdle(UiAutomatorBridge.java: 112）AndroidRuntime：android.support.test.uiautomator.UiAutomatorBridge.waitForIdle（UiAutomatorBridge.java:107）
AndroidRuntime: 在 android.support.test.uiautomator.QueryController.findAccessibilityNodeInfo(QueryController.java:143) AndroidRuntime: 在 android.support.test.uiautomator.QueryController.findAccessibilityNodeInfo(QueryController.java:138) AndroidRuntime: 在 android.support.test .uiautomator.UiObject.findAccessibilityNodeInfo(UiObject.java:188) AndroidRuntime: 在 android.support.test.uiautomator.UiObject.getChildCount(UiObject.java:1