Change how memory policy is configured

Should be a mostly no-op but adds a handful of new options

* Adds a 'MemoryPolicy' to mostly consolidate memory settings
* Moves trim handling into HWUI proper
* Adds settings for UI hidden & context destruction that's not
  dependent on TRIM signals
* Treats persistent process the same as system_server
* Tweaks HardwareBitmapUploader timeout to reduce churn

Bug: 245565051
Test: builds & boots

Change-Id: I1f1b3db884ef7fa45ff2556436464a99440b998e
diff --git a/libs/hwui/Android.bp b/libs/hwui/Android.bp
index b11e542..29f3773 100644
--- a/libs/hwui/Android.bp
+++ b/libs/hwui/Android.bp
@@ -521,6 +521,7 @@
         "Interpolator.cpp",
         "LightingInfo.cpp",
         "Matrix.cpp",
+        "MemoryPolicy.cpp",
         "PathParser.cpp",
         "Properties.cpp",
         "PropertyValuesAnimatorSet.cpp",