In the damaged() method do a callback up to Java code in Desktop that
invalidates the view. For now store the view in a static field, but need to do
that in a cleaner way eventually. There might in some circumstancest be
several instances of the Desktop activity present. Obviously should also run
just one LO thread.

Get rid of the temporary self-invalidattion in onDraw() silliness.

Start the LO thread that runs soffice_main() from Java, not from native
code. Apparently only threads created from Java have proper class loaders in
Android.

No need for an own DoReleaseYield() in AndroidSalInstance, the one in the
SvpSalInstance base class does what needs to be done.

Change-Id: I4cb85b352fca1f1375f726620ec8c93d2047f113