[Android compile bot] Increase # of sync threads
[Android compile bot] Increase # of sync threads

Bug: skia:
Change-Id: Ief89c16b4a04f8ae846ee4dacfc64f2bc67ff2c1
Reviewed-on: https://skia-review.googlesource.com/c/164762
Reviewed-by: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot