DexOpt anything in /system on /cache

Allow system property to disable use of /cache for dexfiles.

(manually cherry-picked commit 15d27bbe10e307136e081bedb7cf25131896f1cb)
dvm: Bring back the ANDROID_DATA override

This got broken by the split-cache patch, and it's impacting the
CTS vm unit. Fixit.

Change-Id: I602824afef19c92a4d2c1702d10c8f0315277227
libdex: Skip the dexroot-on-cache stuff for user builds

Change-Id: I432b96ae3e25977ea17558b4a3f8ca90903cb5b5
debug: allow ability to hide GC freed lines in logcat

use setprop dalvik.vm.debug.alloc 0 to disable these noisy logs...

Change-Id: I8692b941901b43d33ea9ee30c288a47b6a3be3b1
Disable Dalvik spam by default

Reverse the logic: use "dalvik.vm.debug.alloc=1" to see these lines.

Change-Id: Id58de1dd09467c2327f76d37eeb926b712d6af52
Unbreak building host modules

bionic is now a dependency for properties

Change-Id: Icd406e639ca297244ab809f523c6830c2240d20b
libdex: Invert the default for dexopt-on-cache

The growth of /system apps and total /data space are making this
device-breaking (insufficient space to dexopt everything to
/cache), pointless (/data has more than enough room to hold
the cache), and in some cases, both.
The default behavior is now the same as mainline Android's: dexopt
everything to /data. Set dalvik.vm.dexopt-data-only=0 to change
that and dexopt /system apps to /cache. If you do that, make sure
your /cache can accomodate double the size of the dex classes in
system, since in some extreme cases that has been observed during
dex2oat

Change-Id: Ia99655731c882e54bdc85293c467288fb4dc65df