Read page-defined hdf vars for sdk from a central file.
Read page-defined hdf vars for sdk from a central file.

Change-Id: I3a38492c5ae44f810a720957291d7e94e1e7d8ea

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