libbinder_ndk: array 'Allocator'->'ArrayAllocator'

This was confusing because we have 'stringAllocator' which allocates
a string, not an array of strings 'stringArrayAllocator'.

Bug: 111445392
Test: android.binder.cts
Change-Id: I0de04899a4b02160a85693f66cb50f859e738587
3 files changed