Android: Remove enable_incremental_javac and jmake

enable_incremental_javac uses jmake which does not work with java
annotation processors (e.g. Dagger etc) that we are now using. It is not
worth the engineering time and complexity to maintain and is currently
broken.

Removing it in favour of spending more dev time and resources to
optimizes javac usage. Also simplify javac.py logic.

Bug: 930737
Change-Id: Ic31d1b806a81601145696970249e762ed7b3251a
Reviewed-on: https://chromium-review.googlesource.com/c/1478991
Commit-Queue: Peter Wen <wnwen@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633890}
30 files changed