Remove bootclasspathApiInfo

Previously, the bootclasspathApiInfo was only used for tests and follow
up changes will need to provide the stub dex jars. This change moves
the stubJarsByKind into HiddenAPIInfo and removes bootclasspathApiInfo
and the corresponding provider.

Bug: 179354495
Test: m nothing
Change-Id: I5459c56de561c053ed671dc9d5cb3ee4820c0ee8