test: Fix 004-JniTest for javac/dx

Add 'placeholder' FastNative/CriticalNative annotations that are built
with javac, but then the class files are removed before
jar/desugar/dx/etc.

Bug: 36902714
Test: ANDROID_COMPILE_WITH_JACK=false art/test.py
Change-Id: Ia5a284c94bc4a5ae999ca7a2018b16623de8b508
4 files changed