onclite: Enable usage of dex2oat64

Use 64-bit dex2oat for better dexopt time.

Bug: 153380900
Test: boot and install an application
Change-Id: I3e7a6e6e9385ff6564d1a2e6dda004ebb061f095
(cherry picked from commit 126f03be80f57a8a0411842011152d9381589b78)
Merged-In: I3e7a6e6e9385ff6564d1a2e6dda004ebb061f095

system_ext.prop

+# Dalvik
+dalvik.vm.dex2oat64.enabled=true
+
 # DPM
 persist.vendor.dpm.feature=11