Modify the decoding logic in the FD case when a purgeable flag is set, and lower the threshold of bitmap size for using ashmem().
Modify the decoding logic in the FD case when a purgeable flag is set,
and lower the threshold of bitmap size for using ashmem().

For the decoding logic, we now go through the "non-purgeable" path if isShareable is false,
irrespective of the value of the purgeable flag.

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base