Set up environmental variable PATH before calling releasetools scripts.
Set up environmental variable PATH before calling releasetools scripts.

Some releasetools python sripts rely on $PATH to search for the
executables. With this change, you don't need to run lunch even after you
change the build system variable OUT_DIR.

Bug: 19320328
Change-Id: Ia44b11084fb1bdcceb60b1d33cb7e460c9b705a8

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build