Hold a ClassLoader reference in NativeAllocationRegistry.

So that the native library isn't unloaded before we have a chance to
call the freeFunction.

Bug: 28406866

(cherry picked from commit 7d3c7390a8cbeff12fe790e5d12da6e07cf8c298)

Change-Id: I38edb9ba6855ef98743001e4bbf4fd80fb27873d
1 file changed