INTERNAL_LRU_CACHE_SIZE

This is not a public API, it's only public so that we can evaluate the effectiveness of different cache size in tests in a different module.

LRU cache size of 3000 is a sweet spot to balance hits vs memory usage. This is based on running InstrumentationLeakDetectorTest a bunch of time on a Pixel 2 XL API 28. Hit count was ~120K, miss count ~290K