limit Android test tasks to first 4 cores

Read 'f' as 0b1111 or 0b00001111.

This is a hack so I don't have to keep plugging and unplugging my Pixel
3 when I get texts or want to change the music, letting me instead use
a Galaxy S9 with the first few cores good for FP16 and the last bad.

Change-Id: Id8d5e481a430deb28cc0d6f9cc767b75a96313e0
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/216368
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
diff --git a/build/android b/build/android
index 273f692..0463652 100644
--- a/build/android
+++ b/build/android
@@ -20,7 +20,7 @@
               then $
                   adb push --sync profiles /data/local/tmp >/dev/null; $
                   adb push $in /data/local/tmp/$in >/dev/null; $
-                  adb shell "cd /data/local/tmp; ./$in" > $out; $
+                  adb shell "cd /data/local/tmp; taskset f ./$in" > $out; $
               else touch $out; fi
     description = run $in
 include build/common