net-test: deflake 4.19 entropy installation

Bug: 118651133
Change-Id: I00e0ab757d0776c425802b60f5d60d5195a3f2dc
diff --git a/net/test/net_test.sh b/net/test/net_test.sh
index 0c3a3ad..1444da3 100755
--- a/net/test/net_test.sh
+++ b/net/test/net_test.sh
@@ -4,7 +4,7 @@
 
   # In kernel/include/uapi/linux/random.h RNDADDENTROPY is defined as
   # _IOW('R', 0x03, int[2]) =(R is 0x52)= 0x40085203 = 1074287107
-  python 3>/dev/random <<EOF
+  /usr/bin/python 3>/dev/random <<EOF
 import fcntl, struct
 rnd = '${entropy}'.decode('hex')
 fcntl.ioctl(3, 0x40085203, struct.pack('ii', len(rnd) * 8, len(rnd)) + rnd)