Don't use finalize on ActivityView to cleanup.

Use a static object to contain the IActivityContainer reference
rather than storing it directly in the ActivityView itself. Then
when the ActivityView gives up the reference we can use a clean
finalize() call to release the IActivityContainer.

Fixes bug 14184756.

Change-Id: I7e05fcce3040b2b958f7c9cd030d5e3b745f3169