Updating build/config setup to refresh adb path name after a rebuild.

Bug: 24473359

Test: Treehugger
Change-Id: I706e24a8ba7b75a381e9efe48d5db2d49c0f4da6

envsetup.sh

diff --git a/envsetup.sh b/envsetup.sh
index 8b70dc4..9a0cd97 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -1075,6 +1075,10 @@
     echo "can't find Android.mk"
 }
 
+function adb() {
+   `which adb` "${@}"
+}
+
 # simplified version of ps; output in the form
 # <pid> <procname>
 function qpid() {