Clients can register for listening to changes in procstates and if
they are only interested in knowing if the procstate crosses a certain
threshold, they can specify a "cutpoint" and they will only get
a callback if the procstate crosses that "cutpoint" but clients cannot
use this if they are also interested in changes in capabilities. So,
add a way for clients to use the "cutpoint" facility and also listen
to changes in capabilities.
Bug: 177641226
Test: atest services/tests/servicestests/src/com/android/server/am/ActivityManagerServiceTest.java
Test: atest services/tests/servicestests/src/com/android/server/am/UidObserverControllerTest.java
Test: atest ./tests/cts/hostside/src/com/android/cts/net/HostsideRestrictBackgroundNetworkTests.java
Change-Id: I1198e602ca81382975500b10f930dacfd16919e3