Appurify bot: don't use flags that visualbench doesn't support

tools/buildbot_spec.json

 {
   "Build-Mac10.8-Clang-Arm7-Debug-Android": {
     "build_targets": [
       "most"
     ], 
     "builder_cfg": {
       "compiler": "Clang", 
       "configuration": "Debug", 
       "extra_config": "Android", 
       "is_trybot": false, 
@@ skipping 1835 matching lines @@
       "image", 
       "decode", 
       "Hopstarter-Mac-Folders-Apple.ico", 
       "--match", 
       "~tabl_mozilla_0", 
       "~desk_yahoonews_0"
     ], 
     "do_perf_steps": true, 
     "do_test_steps": false, 
     "env": {
-      "BUILDTYPE": "Debug", 
       "GYP_DEFINES": "skia_arch_type=arm skia_warnings_as_errors=0"
     }, 
     "nanobench_flags": [
-      "--scales", 
-      "1.0", 
-      "1.1", 
-      "--config", 
-      "565", 
-      "8888", 
-      "gpu", 
-      "nonrendering", 
-      "angle", 
-      "hwui", 
-      "msaa4", 
-      "nvprmsaa4", 
       "--match", 
       "~blurroundrect", 
       "~patch_grid", 
       "~desk_carsvg"
     ], 
     "upload_dm_results": true, 
     "upload_perf_results": true
   }, 
   "Perf-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Release-Trybot": {
     "build_targets": [
@@ skipping 2016 matching lines @@
       "~blurroundrect", 
       "~patch_grid", 
       "~desk_carsvg", 
       "~keymobi", 
       "~path_hairline"
     ], 
     "upload_dm_results": true, 
     "upload_perf_results": false
   }
 }