Introduce trimMemory to AppIconCacheManager

This CL adds a method to trim lrucache size dynamically based on the
level of onLowMemory to avoid calling evictAll to frequently, and to make cache resize more reasonable.

Bug: 259630755
Test: atest AppIconCacheManagerTest -c

Change-Id: I1b9692a0fad8c13722da4906cf844232707e74b2
2 files changed