tests: Remove obsolete testdata files.

testdata/jarsigned.zip and testdata/unsigned.zip became dead since
commit 43291860 ("Refactor existing
tests to use gtest").

testdata/patch.bsdiff became dead when applypatch/applypatch.sh was
deleted (commit c3ef089d).

Test: Run recovery_unit_test and recovery_component_test.
Change-Id: Ie1a7f8850878593fcb7d4554759a539271ffb207