Define the Request and Provider Info as part of the UI protocol.

The CredMan selector UI will expect request/provider info from the
launching intent. ProviderInfo contains metadata and entry info for a
single provider. RequestInfo contains metadata about the app request
that initiated this ui flow.

Test: deployed locally
Bug: 247855226
Change-Id: I3348ec582920d7d8019b272b8fc2b3c2d48404c6