libbinder_ndk: dump class ptrs in assoc. failure

We know nothing about them if they mismatch now. This could help us
figure out certain kind of memory corruption issues or, if we dump
process memory and have access to mapping information, determine where
the globals that refer to these different classes come from
(AIBinder_Class ptrs are usually stored in globals).

Bug: 195473723
Test: see log in logcat
Change-Id: I3010b62d70a63114fa4610d25860d3602740e185