Remove ojluni.jaif and associated machinery.

This removes ojluni.jaif, which no longer contains any annotations
data. It removes annotated_java_files.bp, which contained a list of
files mentioned in ojluni.jaif. It removes the tooling and build rules
around keeping annotated_java_files.bp up to date. And it removes all
references to the generated source files from the libcore droiddoc
targets.

Bug: 111639530
Test: `make docs` output is unaffected
Test: `make core-docs`
Change-Id: I44ae36c3940abb0173a64669564b244b72c7ff9f