analyze_bcpf: Compute hidden_api package properties

Analyzes the signatures of the class members contained within the
bootclasspath_fragment to construct the split_packages,
single_packages and package_prefixes hidden_api properties that are
necessary to remove the internal implementation details from the
hidden API flags.

Bug: 202154151
Test: m analyze_bcpf && analyze_bcpf --bcpf art-bootclasspath-fragment
      m analyze_bcpf && analyze_bcpf --bcpf art-bootclasspath-fragment --fix
      m analyze_bcpf && analyze_bcpf --bcpf com.android.mediaprovider-bootclasspath-fragment --fix
      atest --host analyze_bcpf_test
Change-Id: I4a8e5a8bfee2a44775e714b9226cd4a7382e0123