Fix flaky test for persistent notifications

Persistent notifications test sometimes fails due
to setup activity doesn't exit due to failed intent.
Adding setup exit command when on device tests are starting and
adding timeout for transition.

Test: m Settings && adb install -r $ANDROID_PRODUCT_OUT/system_ext/priv-app/Settings/Settings.apk
Flag: EXEMPT bugfix
Bug: 349820489
Change-Id: Iaf1c1f481612367bbce919b27e89f88a24abb582