Don't start two pane for singleInstance deep links

If the activity's launch mode is "singleInstance", it can't be embedded
in Settings since it will be created in a new task.

Bug: 229371407
Test: adb shell am start -a android.settings.NETWORK_OPERATOR_SETTINGS
Change-Id: I1689d860151182cd9e97d9e4fd65d30a8804a570