ResourceManager: Disable APK Assets cache.

The WeakReference based cache of Assets in use elsewhere in the
process remains unchanged.

Note that this change is larger than it needs to be because it is
an error to create an LruCache of size zero.

There seems to be no measurable difference as measured by the standard
app startup benchmarks.

Test: atest -v google/perf/app-startup/benchmark-app-hermetic/cold-dropcache-test
Bug: 111385832
Change-Id: I432c069e90124e884bddc5cd5be43a28e1b16d07