Add non-system overlay flag for usb perm dialog

Add private flag SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS for
UsbPermissionActivity.

With this flag, UsbPermissionActivity will not been overlapped with
views which are displayed on system alert window

Bug: 183610267
Test: atest UsbPermissionActivityTest#testHideNonSystemOverlay
Test: check the window private flag of UsbPermissionActivity contains
      SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS or not.
Change-Id: I0863ff347ac3c2300f0dc649a630f55473ee180a
diff --git a/packages/SystemUI/tests/AndroidManifest.xml b/packages/SystemUI/tests/AndroidManifest.xml
index f1c687f..2c9c980 100644
--- a/packages/SystemUI/tests/AndroidManifest.xml
+++ b/packages/SystemUI/tests/AndroidManifest.xml
@@ -93,6 +93,13 @@
         <activity android:name="com.android.systemui.screenshot.RecyclerViewActivity"
                   android:exported="false" />
 
+        <!-- started from UsbDeviceSettingsManager -->
+        <activity android:name=".usb.UsbPermissionActivityTest$UsbPermissionActivityTestable"
+                  android:exported="false"
+                  android:theme="@style/Theme.SystemUI.Dialog.Alert"
+                  android:finishOnCloseSystemDialogs="true"
+                  android:excludeFromRecents="true" />
+
         <provider
             android:name="androidx.lifecycle.ProcessLifecycleOwnerInitializer"
             tools:replace="android:authorities"