Deprecate SSLCertificateSocketFactory

See the bug for the full context, but the short version is that this
class is difficult to use properly, has a number of questionable
methods, ignores the provider system, and largely exists to support
functionality for which there are now standard APIs.

Test: make docs
Change-Id: I3b155b23bba41a72f20c149986318b75fa6d2eb0
Fixes: 112031620