Lint to identify "deprecated at birth" APIs.

Lint to identify "deprecated at birth" APIs.

When API council requests changes, teams regularly perform the
requested refactoring, but simply mark the old APIs as @Deprecated
without @removed, due to internal users.

As part of finalizing an SDK, we should ensure that no new APIs are
marked @Deprecated, since they're typically cleanup that someone
forgot to finish.  This extension to the lint script makes it easy
to identify these cases.

$ python tools/apilint/apilint.py --show-deprecations-at-birth \
        api/current.txt ../../prebuilts/sdk/api/28.txt

$ python tools/apilint/apilint.py --show-deprecations-at-birth \
        api/system-current.txt ../../prebuilts/sdk/system-api/28.txt

Bug: 77588754
Test: manual inspection
Change-Id: Ie9658006bb08f780bee0e503481d3bafec1038a1