Use JNI to access activity manager process state.

After a GC occurs, we use JNI to access activity manager process
state to decide whether or not we will trim.

Change-Id: Iad981e3a7cdc694729d8792cc0f19e0262154388
(cherry picked from commit c39e342317d77e701b4cd01cd5b05902e6512f4b)
3 files changed