[res] Fix the registered shared lib asset caching

We must use the ResourcesManager's ApkAssets cache for the
registered library assets, otherwise each Resources object
is going to create a separate FD and parse the same WebView
apk again, quickly exceeding the system limits for FDs per
process.

+ correctly differentiate the overlays vs apps for the
  registered library paths

Bug: 343567870
Flag: android.content.res.register_resource_paths
Test: atest CtsResourcesTestCases
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c9c0d5eee84bcb8d2db519f2cfadddebe9d35881)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:33f81d22dcbe7127786a8016a333c7d430e99b14)
Merged-In: I089ec2fecc875d758a0a5639e7db77081927a25f
Change-Id: I089ec2fecc875d758a0a5639e7db77081927a25f