Encode use of private API in manifest

If a package is declared to build directly against the platform,
this patch will invoke manifest_fixer.py to encode that information
in the manifest. This information is then used by the framework to
correctly configure the runtime process.

Bug: 113315999
Test: m StorageManager; aapt l -a StorageManager.apk|grep usesNonSdkApi
Change-Id: I53c9728d12380a01b35315fc9c58463e9f5a9f48