Fix the MIPS build.
Fix the MIPS build.

Use an override for the dex2oat Xmx value when cross-compiling.
Bug: 16221224

(cherry picked from commit 7d70f830bce969575b358a39e041e85013881cd4)

Change-Id: Ic13b471c74325e8145a0a9c93a417355505e484a

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