Expose credential manager APIs in View classes

For apps built on tradional View based frameworks, developers
will be expected to set GetCredentialRequest on given views.
For apps built on other frameworks like webview & compose, developers
will set high level requests on View counterparts in that framework, and
then the framework implementation will provide a virtual viewstrucuture to
the autofill manager, including setting the request on virtual view nodes.

Design doc: https://docs.google.com/document/d/16pQ34SsxctR4naB36MsL3gyBfMKbg7luJVWhZrzsQZU/edit?resourcekey=0-0pX-n_b-y9onKdlipfySPw&tab=t.0#bookmark=id.5tn70i6wnp7j
Compose doc: https://docs.google.com/document/d/1fQJiIswR-mG94FIgYhRBG93F-lQ4nh3Xw_88ykT-kjw/edit?usp=sharing

Test: Cts
Bug: 318846139

Change-Id: I55b2a1468fdf3d8e6e810e28b22ea587d03787b2