Only build index and javadoc reports

Only build index and javadoc reports

There was concern that generating all the reports causes builds to take
significantly longer. Disable all reports except for the index page and
javadoc for now. We can add reports one at a time later if we need them
and decide if they add significantly to build times.

I took some benchmarks on my machine.

odlparent build times without this patch:

    Total time: 01:54 min

odlparent build times with this patch:

    Total time: 56.617 s

Change-Id: Ida5e4e8e0846526134ec5ad8c385f46c649776ff
Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>