Increase thread count on internal bot

The new vm has twice the ram

Bug: 224618426
Change-Id: I10c37ff8dd5905a45f75c125b1f58065d32ad6ef
diff --git a/tools/internal_test.py b/tools/internal_test.py
index 0d591ad..df4174f 100755
--- a/tools/internal_test.py
+++ b/tools/internal_test.py
@@ -383,7 +383,7 @@
   log('Running once with hash %s' % git_hash)
   env = os.environ.copy()
   # Bot does not have a lot of memory.
-  env['R8_GRADLE_CORES_PER_FORK'] = '16'
+  env['R8_GRADLE_CORES_PER_FORK'] = '8'
   failed = any([execute(cmd, archive, env) for cmd in TEST_COMMANDS])
   # Gradle daemon occasionally leaks memory, stop it.
   gradle.RunGradle(['--stop'])