Improve Fragment+Loader deprecation Javadoc

Make it clear that the framework versions of
Fragments and Loaders should be replaced with their
identically named versions in the Support Library.

Reference the recent work on Lifecycle as an example
of a Support Library only change that should motivate
developers to switch to the Support Library
equivalents.

Test: Reviewed new Javadoc
BUG: 70336450
Change-Id: I93151fa0a316bba824c2e55f80f7de9d30bed3c6