libprocessgroup: Add support for SetUserProfiles

Provide SetUserProfiles API to apply profiles at UID level.

This enables applying the freezer profile to an entire UID instead of
just individual process cgroups.

Test: bash arg: -p
Test: bash arg: com.haok.nirvana
Test: bash arg: 1
Test: args: [-p, com.haok.nirvana, 1]
Test: arg: "-p"
Test: arg: "com.haok.nirvana"
Test: arg: "1"
Test: data="com.haok.nirvana"
Test: Events injected: 1
Test: ## Network stats: elapsed time=14ms (0ms mobile, 0ms wifi, 14ms not connected)
Test: raven:/ $ ps -eo pid,uid,ppid,name|grep 10266
Test: 2499 10266   823 com.haok.nirvana
Test: 2577 10266   823 com.haok.nirvana:resident
Test: 2584 10266   823 android.media
Test: 2669 10266     1 app_d
Test: 2672 10266     1 app_d
Test: raven:/ $ am force-stop com.haok.nirvana
Test: raven:/ $ ps -eo pid,uid,ppid,name|grep 10266
Test: 1|raven:/ $
Ignore-AOSP-First: Topic with AMS changes which is developed on git_master
Bug: 236708592
Change-Id: I45e34244f9943c217757cf346c9410672a1ce365