core: Remove QCOM BoostFramework and ActivityTrigger

These rely on a bunch of proprietary libs that not
all devices support. CM has its own boosting solution
anyway, rendering these additions unnecessary.

One small, but important change has been omitted from the revert,
that is the addition of ro.sys.fw.bg_apps_limit in the file
services/core/java/com/android/server/am/ProcessList.java.

This reverts the following commits:
81dd8c09 Creating only a single activity trigger module
c35293c3 Framework for LaunchBoost v2 and Frequency aggr during launch.
91338fb3 frameworks: Add custom boost for scroll/fling
911884e1 Perf: Adding hooks for IO prefetcher into framework
f56206d6 BoostFramework to enhance performance during critical scenarios
d841ef62 add network related API into ActivityTrigger
2f1b2812 Set animation scale values for specific activity.
4ea9a4ec frameworks/base: activity pause/stop event triggers
015851c6 frameworks/base: Tap process start event to trigger perf lib.
e14378bf frameworks/base: Add support for low resolution rendering
4d9ec135 ActivityTrigger: New class to invoke when activity starts/resumes

Change-Id: Iafdc3866c39d4e0d51ca2d40931ea9a5baba7de5